Market crash
   HOME

TheInfoList



OR:

A stock market crash is a sudden dramatic decline of stock prices across a major cross-section of a stock market, resulting in a significant loss of paper wealth. Crashes are driven by
panic selling Panic selling is a large-scale selling of an investment that causes a sharp decline in prices. Specifically, an investor wants to sell an investment with little regard to the price obtained. The sale is problematic because the investor is reacting ...
and underlying economic factors. They often follow speculation and economic bubbles. A stock market crash is a
social phenomenon Social phenomena or social phenomenon (singular) are any behaviours, actions, or events that takes place because of social influence, including from contemporary as well as historical societal influences. They are often a result of multifaceted pr ...
where external economic events combine with crowd psychology in a
positive feedback Positive feedback (exacerbating feedback, self-reinforcing feedback) is a process that occurs in a feedback loop which exacerbates the effects of a small disturbance. That is, the effects of a perturbation on a system include an increase in th ...
loop where selling by some market participants drives more market participants to sell. Generally speaking, crashes usually occur under the following conditions: a prolonged period of rising stock prices (a
bull market A market trend is a perceived tendency of financial markets to move in a particular direction over time. Analysts classify these trends as ''secular'' for long time-frames, ''primary'' for medium time-frames, and ''secondary'' for short time-fram ...
) and excessive economic optimism, a market where price–earnings ratios exceed long-term averages, and extensive use of
margin Margin may refer to: Physical or graphical edges *Margin (typography), the white space that surrounds the content of a page *Continental margin, the zone of the ocean floor that separates the thin oceanic crust from thick continental crust *Leaf ...
debt and leverage by market participants. Other aspects such as wars, large corporate hacks, changes in federal laws and regulations, and natural disasters within economically productive areas may also influence a significant decline in the stock market value of a wide range of stocks. Stock prices for corporations competing against the affected corporations may rise despite the crash. There is no numerically specific definition of a stock market crash but the term commonly applies to declines of over 10% in a stock market index over a period of several days. Crashes are often distinguished from
bear markets A market trend is a perceived tendency of financial markets to move in a particular direction over time. Analysts classify these trends as ''secular'' for long time-frames, ''primary'' for medium time-frames, and ''secondary'' for short time-fram ...
(periods of declining stock market prices that are measured in months or years) as crashes include
panic selling Panic selling is a large-scale selling of an investment that causes a sharp decline in prices. Specifically, an investor wants to sell an investment with little regard to the price obtained. The sale is problematic because the investor is reacting ...
and abrupt, dramatic price declines. Crashes are often associated with bear markets; however, they do not necessarily occur simultaneously. Black Monday (1987), for example, did not lead to a bear market. Likewise, the bursting of the Japanese asset price bubble occurred over several years without any notable crashes. Stock market crashes are not common. Crashes are generally unexpected. As
Niall Ferguson Niall Campbell Ferguson FRSE (; born 18 April 1964)Biography
Niall Ferguson
stated, "Before the crash, our world seems almost stationary, deceptively so, balanced, at a set point. So that when the crash finally hits — as inevitably it will — everyone seems surprised. And our brains keep telling us it’s not time for a crash."


Examples


Tulip Mania

Tulip Mania Tulip mania ( nl, tulpenmanie) was a period during the Dutch Golden Age when contract prices for some bulbs of the recently introduced and fashionable tulip reached extraordinarily high levels. The major acceleration started in 1634 and then d ...
(1634-1637), in which some single tulip bulbs allegedly sold for more than 10 times the annual income of a skilled
artisan An artisan (from french: artisan, it, artigiano) is a skilled craft worker who makes or creates material objects partly or entirely by hand. These objects may be functional or strictly decorative, for example furniture, decorative art ...
, is often considered to be the first recorded economic bubble.


Panic of 1907

In 1907 and in 1908, stock prices fell by nearly 50% due to a variety of factors, led by the manipulation of
copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...
stocks by the
Knickerbocker Trust Company The Knickerbocker Trust was a bank based in New York City that was, at one time, among the largest banks in the United States. It was a central player in the Panic of 1907. History The bank was chartered in 1884 by Frederick G. Eldridge, a frie ...
. Shares of
United Copper The United Copper Company was a short-lived United States copper mining business in the early 20th century that played a pivotal role in the Panic of 1907. United Copper was incorporated in 1902 by F. Augustus Heinze, a copper magnate who had tuss ...
rose gradually up to October, and thereafter crashed, leading to panic. Several investment trusts and banks that had invested their money in the stock market fell and started to close down. Further bank runs were prevented due to the intervention of
J. P. Morgan John Pierpont Morgan Sr. (April 17, 1837 – March 31, 1913) was an American financier and investment banker who dominated corporate finance on Wall Street throughout the Gilded Age. As the head of the banking firm that ultimately became known ...
. The panic continued to 1908 and led to the formation of the
Federal Reserve The Federal Reserve System (often shortened to the Federal Reserve, or simply the Fed) is the central banking system of the United States of America. It was created on December 23, 1913, with the enactment of the Federal Reserve Act, after a ...
in 1913.


Wall Street Crash of 1929

The economy grew for most of the
Roaring Twenties The Roaring Twenties, sometimes stylized as Roaring '20s, refers to the 1920s decade in music and fashion, as it happened in Western society and Western culture. It was a period of economic prosperity with a distinctive cultural edge in the ...
. It was a technological golden age, as innovations such as the radio, automobile, aviation, telephone, and the electric power transmission grid were deployed and adopted. Companies that had pioneered these advances, including
Radio Corporation of America The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Com ...
(RCA) and General Motors, saw their stocks soar. Financial corporations also did well, as Wall Street bankers floated
mutual fund A mutual fund is a professionally managed investment fund that pools money from many investors to purchase securities. The term is typically used in the United States, Canada, and India, while similar structures across the globe include the SICAV ...
companies (then known as investment trusts) like the Goldman Sachs Trading Corporation. Investors were infatuated with the returns available in the stock market, especially by the use of
leverage Leverage or leveraged may refer to: *Leverage (mechanics), mechanical advantage achieved by using a lever * ''Leverage'' (album), a 2012 album by Lyriel *Leverage (dance), a type of dance connection *Leverage (finance), using given resources to ...
through margin debt (i.e., borrowing money from your stockbroker to finance part of your purchase of stocks, using the bought securities as collateral). On August 24, 1921, the
Dow Jones Industrial Average The Dow Jones Industrial Average (DJIA), Dow Jones, or simply the Dow (), is a stock market index of 30 prominent companies listed on stock exchanges in the United States. The DJIA is one of the oldest and most commonly followed equity inde ...
(DJIA) was at 63.9. By September 3, 1929, it had risen more than sixfold to 381.2. It did not regain this level for another 25 years. By the summer of 1929, it was clear that the economy was contracting, and the stock market went through a series of unsettling price declines. These declines fed investor anxiety, and events came to a head on October 24, 28, and 29 (known respectively as
Black Thursday Black Thursday is a term used to refer to typically negative, notable events that have occurred on a Thursday. It has been used in the following cases: *6 February 1851, bushfires in Victoria, Australia. *18 September 1873, during the Panic of ...
,
Black Monday Black Monday refers to specific Mondays when undesirable or turbulent events have occurred. It has been used to designate massacres, military battles, and stock market crashes. Historic events *1209, Dublin – when a group of 500 recently arriv ...
, and
Black Tuesday The Wall Street Crash of 1929, also known as the Great Crash, was a major American stock market crash that occurred in the autumn of 1929. It started in September and ended late in October, when share prices on the New York Stock Exchange coll ...
). On Black Monday, the DJIA fell 38.33 points to 260, a drop of 12.8%. The deluge of selling overwhelmed the
ticker tape Ticker tape was the earliest electrical dedicated financial communications medium, transmitting stock price information over telegraph lines, in use from around 1870 through 1970. It consisted of a paper strip that ran through a machine called ...
system that normally gave investors the current prices of their shares.
Telephone line A telephone line or telephone circuit (or just line or circuit industrywide) is a single-user circuit on a telephone communication system. It is designed to reproduce speech of a quality that is understandable. It is the physical wire or ot ...
s and telegraphs were clogged and were unable to cope. This information vacuum only led to more fear and panic. The technology of the New Era, previously much celebrated by investors, now served to deepen their suffering. The following day, Black Tuesday, was a day of chaos. Forced to liquidate their stocks because of
margin call ''Margin Call'' is a 2011 American drama film written and directed by J. C. Chandor in his feature directorial debut. The principal story takes place over a 24-hour period at a large Wall Street investment bank during the initial stages of the ...
s, overextended investors flooded the exchange with sell orders. The Dow fell 30.57 points to close at 230.07 on that day. The glamour stocks of the age saw their values plummet. Across the two days, the DJIA fell 23%. By the end of the weekend of November 11, 1929, the index stood at 228, a cumulative drop of 40% from the September high. The markets rallied in succeeding months, but it was a temporary recovery that led unsuspecting investors into further losses. The DJIA lost 89% of its value before finally bottoming out in July 1932. The crash was followed by the Great Depression, the worst
economic crisis An economy is an area of the production, distribution and trade, as well as consumption of goods and services. In general, it is defined as a social domain that emphasize the practices, discourses, and material expressions associated with th ...
of modern times, which plagued the stock market and Wall Street throughout the 1930s.


October 19, 1987

The mid-1980s were a time of strong economic optimism. From August 1982 to its peak in August 1987, the
Dow Jones Industrial Average The Dow Jones Industrial Average (DJIA), Dow Jones, or simply the Dow (), is a stock market index of 30 prominent companies listed on stock exchanges in the United States. The DJIA is one of the oldest and most commonly followed equity inde ...
(DJIA) rose from 776 to 2722. The rise in market indices for the 19 largest markets in the world averaged 296% during this period. The average number of shares traded on the
New York Stock Exchange The New York Stock Exchange (NYSE, nicknamed "The Big Board") is an American stock exchange in the Financial District of Lower Manhattan in New York City. It is by far the world's largest stock exchange by market capitalization of its listed ...
rose from 65 million shares to 181 million shares. The crash on October 19, 1987,
Black Monday Black Monday refers to specific Mondays when undesirable or turbulent events have occurred. It has been used to designate massacres, military battles, and stock market crashes. Historic events *1209, Dublin – when a group of 500 recently arriv ...
, was the climactic culmination of a market decline that had begun five days before on October 14. The DJIA fell 3.81% on October 14, followed by another 4.60% drop on Friday, October 16. On Black Monday, the DJIA plummeted 508 points, losing 22.6% of its value in one day. The
S&P 500 Index The Standard and Poor's 500, or simply the S&P 500, is a stock market index tracking the stock performance of 500 large companies listed on stock exchanges in the United States. It is one of the most commonly followed equity indices. As of D ...
dropped 20.4%, falling from 282.7 to 225.06. The
NASDAQ Composite The Nasdaq Composite ( ticker symbol ^IXIC) is a stock market index that includes almost all stocks listed on the Nasdaq stock exchange. Along with the Dow Jones Industrial Average and S&P 500, it is one of the three most-followed stock market ind ...
lost only 11.3%, not because of restraint on the part of sellers, but because the NASDAQ
market system A market system (or market ecosystem) is any systematic process enabling many market players to offer and demand: helping buyers and sellers interact and make deals. It is not just the price mechanism but the entire system of regulation, qual ...
failed. Deluged with sell orders, many stocks on the NYSE faced
trading halt A trading halt occurs in the U.S. when a stock exchange stops trading on a specific security for a certain time period. The halt, which can happen a few times a day per security if FINRA deems it, usually lasts for one hour, but is not limited ...
s and delays. Of the 2,257 NYSE-listed stocks, there were 195 trading delays and halts during the day. The NASDAQ market fared much worse. Because of its reliance on a "market making" system that allowed
market maker A market maker or liquidity provider is a company or an individual that quotes both a buy and a sell price in a tradable asset held in inventory, hoping to make a profit on the ''bid–ask spread'', or ''turn.'' The benefit to the firm is that i ...
s to withdraw from trading, liquidity in NASDAQ stocks dried up. Trading in many stocks encountered a pathological condition where the
bid price A bid price is the highest price that a buyer (i.e., bidder) is willing to pay for some goods. It is usually referred to simply as the "bid". In bid and ask, the bid price stands in contrast to the ask price or "offer", and the difference betwe ...
for a stock exceeded the
ask price Ask price, also called offer price, offer, asking price, or simply ask, is the price a seller states they will accept. The seller may qualify the stated asking price as firm or negotiable. Firm means the seller is implying that the price is fix ...
. These "locked" conditions severely curtailed trading. On October 19, trading in
Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washin ...
shares on the NASDAQ lasted a total of 54 minutes. The crash was the greatest single-day loss that Wall Street had ever suffered in continuous trading up to that point. Between the start of trading on October 14 to the close on October 19, the DJIA lost 760 points, a decline of over 31%. In October 1987, all major world markets crashed or declined substantially. The FTSE 100 Index lost 10.8% on that Monday and a further 12.2% the following day. The least affected was Austria (a fall of 11.4%) while the most affected was Hong Kong with a drop of 45.8%. Out of 23 major industrial countries, 19 had a decline greater than 20%. Despite fears of a repeat of the Great Depression, the market rallied immediately after the crash, posting a record one-day gain of 102.27 the very next day and 186.64 points on Thursday, October 22. It took only two years for the Dow to recover completely; by September 1989, the market had regained all of the value it had lost in the 1987 crash. The DJIA gained 0.6% during calendar year 1987. No definitive conclusions have been reached on the reasons behind the 1987 Crash. Stocks had been in a multi-year bull run and market price–earnings ratios in the U.S. were above the post-war average. The S&P 500 was trading at 23 times earnings, a postwar high and well above the average of 14.5 times earnings.
Herd behavior Herd behavior is the behavior of individuals in a group acting collectively without centralized direction. Herd behavior occurs in animals in herds, packs, bird flocks, fish schools and so on, as well as in humans. Voting, demonstrations, riots ...
and psychological feedback loops play a critical part in all stock market crashes but analysts have also tried to look for external triggering events. Aside from the general worries of stock market overvaluation, blame for the collapse has been apportioned to such factors as
program trading Program trading is a type of trading in securities, usually consisting of baskets of fifteen stocks or more that are executed by a computer program simultaneously based on predetermined conditions. Program trading is often used by hedge funds an ...
, portfolio insurance and derivatives, and prior news of worsening
economic indicator An economic indicator is a statistic about an economic activity. Economic indicators allow analysis of economic performance and predictions of future performance. One application of economic indicators is the study of business cycles. Economic ...
s (i.e. a large U.S. merchandise
trade deficit The balance of trade, commercial balance, or net exports (sometimes symbolized as NX), is the difference between the monetary value of a nation's exports and imports over a certain time period. Sometimes a distinction is made between a balance ...
and a falling
U.S. dollar The United States dollar ( symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the officia ...
, which seemed to imply future interest rate hikes). One of the consequences of the 1987 Crash was the introduction of the circuit breaker or
trading curb A trading curb (typically known as a circuit breaker in Wall Street parlance) is a financial regulatory instrument that is in place to prevent stock market crashes from occurring, and is implemented by the relevant stock exchange organization. Si ...
on the NYSE. Based upon the idea that a cooling-off period would help dissipate
panic selling Panic selling is a large-scale selling of an investment that causes a sharp decline in prices. Specifically, an investor wants to sell an investment with little regard to the price obtained. The sale is problematic because the investor is reacting ...
, these mandatory market shutdowns are triggered whenever a large pre-defined market decline occurs during the
trading day In business, the trading day or regular trading hours (RTH) is the time span that a stock exchange is open, as opposed to electronic or extended trading hours (ETH). For example, the New York Stock Exchange is, as of 2020, open from 9:30 AM Easte ...
.


Crash of 2008–2009

On September 15, 2008, the
bankruptcy of Lehman Brothers The bankruptcy of Lehman Brothers on September 15, 2008, was the climax of the subprime mortgage crisis. After the financial services firm was notified of a pending credit downgrade due to its heavy position in subprime mortgages, the Federal ...
and the collapse of Merrill Lynch along with a liquidity crisis of
American International Group American International Group, Inc. (AIG) is an American multinational finance and insurance corporation with operations in more than 80 countries and jurisdictions. , AIG companies employed 49,600 people.https://www.aig.com/content/dam/aig/amer ...
, all primarily due to exposure to packaged subprime loans and credit default swaps issued to insure these loans and their issuers, rapidly devolved into a global crisis. This resulted in several
bank failure A bank failure occurs when a bank is unable to meet its obligations to its depositors or other creditors because it has become insolvent or too illiquid to meet its liabilities. A bank usually fails economically when the market value of its asset ...
s in Europe and sharp reductions in the value of stocks and commodities worldwide. The failure of banks in Iceland resulted in a devaluation of the
Icelandic króna The króna or krona (sometimes called Icelandic crown; sign: kr; code: ISK) is the currency of Iceland. Iceland is the second-smallest country by population, after the Seychelles, to have its own currency and monetary policy. Name Like the ...
and threatened the government with bankruptcy. Iceland obtained an emergency loan from the
International Monetary Fund The International Monetary Fund (IMF) is a major financial agency of the United Nations, and an international financial institution, headquartered in Washington, D.C., consisting of 190 countries. Its stated mission is "working to foster glo ...
in November. In the United States, 15 banks failed in 2008, while several others were rescued through government intervention or acquisitions by other banks. On October 11, 2008, the head of the
International Monetary Fund The International Monetary Fund (IMF) is a major financial agency of the United Nations, and an international financial institution, headquartered in Washington, D.C., consisting of 190 countries. Its stated mission is "working to foster glo ...
(IMF) warned that the world financial system was teetering on the "brink of systemic meltdown". The economic crisis caused countries to close their markets temporarily. On October 8, the
Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
n stock market halted trading, after a 10% drop in one day. ''
The Times ''The Times'' is a British daily national newspaper based in London. It began in 1785 under the title ''The Daily Universal Register'', adopting its current name on 1 January 1788. ''The Times'' and its sister paper '' The Sunday Times'' (f ...
'' of London reported that the meltdown was being called the ''Crash of 2008'', and older traders were comparing it with Black Monday in 1987. The fall that week of 21% compared to a 28.3% fall 21 years earlier, but some traders were saying it was worse. "At least then it was a short, sharp, shock on one day. This has been relentless all week." Other media also referred to the events as the "Crash of 2008". From October 6–10, 2008, the Dow Jones Industrial Average (DJIA) closed lower in all five sessions. Volume levels were record-breaking. The DJIA fell over 1,874 points, or 18%, in its worst weekly decline ever on both a points and percentage basis. The S&P 500 fell more than 20%. The week also set 3 top ten NYSE Group Volume Records with October 8 at #5, October 9 at #10, and October 10 at #1. Having been suspended for three successive trading days (October 9, 10, and 13), the Icelandic stock market reopened on 14 October, with the main index, the
OMX Iceland 15 The OMX Iceland 15 (formerly the ICEX15) is a defunct stock market index which consisted of a maximum of 15 companies listed on the OMX Iceland Stock Exchange with the highest market capitalization. At the final official review of the index effect ...
, closing at 678.4, which was about 77% lower than the 3,004.6 at the close on October 8. This reflected that the value of the three big banks, which had formed 73.2% of the value of the OMX Iceland 15, had been set to zero. On October 24, 2008, many of the world's stock exchanges experienced the worst declines in their history, with drops of around 10% in most indices. In the U.S., the DJIA fell 3.6%, although not as much as other markets. The
United States dollar The United States dollar ( symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the officia ...
and Japanese yen soared against other major currencies, particularly the
British pound Sterling (abbreviation: stg; Other spelling styles, such as STG and Stg, are also seen. ISO code: GBP) is the currency of the United Kingdom and nine of its associated territories. The pound ( sign: £) is the main unit of sterling, an ...
and Canadian dollar, as world investors sought safe havens. Later that day, the deputy governor of the Bank of England, Charlie Bean, suggested that "This is a once in a lifetime crisis, and possibly the largest financial crisis of its kind in human history." By March 6, 2009 the DJIA had dropped 54% to 6,469 from its peak of 14,164 on October 9, 2007, over a span of 17 months, before beginning to recover.


Covid-19 pandemic (2020)

During the week of February 24–28, 2020, stock markets dropped as the
COVID-19 pandemic The COVID-19 pandemic, also known as the coronavirus pandemic, is an ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The novel virus was first identi ...
spread globally. The FTSE 100 dropped 13%, while the DJIA and S&P 500 Index dropped 11-12% in the biggest downward weekly drop since the
financial crisis of 2007–2008 Finance is the study and discipline of money, currency and capital assets. It is related to, but not synonymous with economics, the study of production, distribution, and consumption of money, assets, goods and services (the discipline of fi ...
. On Monday, March 9, 2020, after the launch of the 2020 Russia–Saudi Arabia oil price war, the FTSE and other major European stock market indices fell by nearly 8%. Asian markets fell sharply and the S&P 500 Index dropped 7.60%. The Italian FTSE MIB fell 2,323.98 points, or 11.17%. On March 12, 2020, a day after US President
Donald Trump Donald John Trump (born June 14, 1946) is an American politician, media personality, and businessman who served as the 45th president of the United States from 2017 to 2021. Trump graduated from the Wharton School of the University of P ...
announced a travel ban from Europe, stock prices again fell sharply. The DJIA declined 9.99% — the largest daily decline since Black Monday (1987) — despite the
Federal Reserve The Federal Reserve System (often shortened to the Federal Reserve, or simply the Fed) is the central banking system of the United States of America. It was created on December 23, 1913, with the enactment of the Federal Reserve Act, after a ...
announcing it would inject $1.5 trillion into money markets. The S&P 500 and the Nasdaq each dropped by approximately 9.5%. The major European stock market indexes all fell over 10%. On March 16, 2020, after it became clear that a
recession In economics, a recession is a business cycle contraction when there is a general decline in economic activity. Recessions generally occur when there is a widespread drop in spending (an adverse demand shock). This may be triggered by various ...
was inevitable, the DJIA dropped 12.93%, or 2,997 points, the largest point drop since Black Monday (1987), surpassing the drop in the prior week, the Nasdaq Composite dropped 12.32%, and the S&P 500 Index dropped 11.98%. By the end of May 2020, the stock market indices briefly recovered to their levels at the end of February 2020. In June 2020 the Nasdaq surpassed its pre-crash high followed by the S&P 500 in August and the Dow in November.


Mathematical theory


Random walk theory

The conventional assumption is that stock markets behave according to a random
log-normal distribution In probability theory, a log-normal (or lognormal) distribution is a continuous probability distribution of a random variable whose logarithm is normally distributed. Thus, if the random variable is log-normally distributed, then has a norma ...
. Among others, mathematician Benoit Mandelbrot suggested as early as 1963 that the statistics prove this assumption incorrect. Mandelbrot observed that large movements in prices (i.e. crashes) are much more common than would be predicted from a log-normal distribution. Mandelbrot and others suggested that the nature of market moves is generally much better explained using non-linear analysis and concepts of chaos theory. This has been expressed in non-mathematical terms by
George Soros George Soros ( name written in eastern order), (born György Schwartz, August 12, 1930) is a Hungarian-American businessman and philanthropist. , he had a net worth of US$8.6 billion, Note that this site is updated daily. having donated mo ...
in his discussions of what he calls reflexivity of markets and their non-linear movement. George Soros said in late October 1987, 'Mr.
Robert Prechter Robert R. Prechter Jr. (born March 25, 1949) is an American financial author, and stock market analyst, known for his financial forecasts using the Elliott Wave Principle. Prechter is an author and co-author of 14 books, and editor of 2 books, and ...
's reversal proved to be the crack that started the avalanche'.


Self-organized criticality

Research at the
Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...
suggests that there is evidence that the frequency of stock market crashes follows an inverse cubic power law. This and other studies such as
Didier Sornette Didier Sornette (born June 25, 1957 in Paris) is a French researcher studying subjects including complex systems and risk management. He is Professor on the Chair of Entrepreneurial Risks at the Swiss Federal Institute of Technology Zurich (ETH ...
's work suggest that stock market crashes are a sign of
self-organized criticality Self-organized criticality (SOC) is a property of dynamical systems that have a critical point as an attractor. Their macroscopic behavior thus displays the spatial or temporal scale-invariance characteristic of the critical point of a phase ...
in financial markets.


Lévy flight

In 1963, Mandelbrot proposed that instead of following a strict
random walk In mathematics, a random walk is a random process that describes a path that consists of a succession of random steps on some mathematical space. An elementary example of a random walk is the random walk on the integer number line \mathbb Z ...
, stock price variations executed a
Lévy flight A Lévy flight is a random walk in which the step-lengths have a Lévy distribution, a probability distribution that is heavy-tailed. When defined as a walk in a space of dimension greater than one, the steps made are in isotropic random direct ...
. A Lévy flight is a random walk that is occasionally disrupted by large movements. In 1995, Rosario Mantegna and Gene Stanley analyzed a million records of the
S&P 500 Index The Standard and Poor's 500, or simply the S&P 500, is a stock market index tracking the stock performance of 500 large companies listed on stock exchanges in the United States. It is one of the most commonly followed equity indices. As of D ...
, calculating the returns over a five-year period. Researchers continue to study this theory, particularly using computer simulation of crowd behavior, and the applicability of models to reproduce crash-like phenomena.


Result of investor imitation

In 2011, using statistical analysis tools of complex systems, research at the
New England Complex Systems Institute The New England Complex Systems Institute (NECSI) is an independent American research institution and think tank dedicated to advancing analytics and its application to the challenges of society, and the interaction of complex systems with the envi ...
found that the panics that lead to crashes come from a dramatic increase in
imitation Imitation (from Latin ''imitatio'', "a copying, imitation") is a behavior whereby an individual observes and replicates another's behavior. Imitation is also a form of that leads to the "development of traditions, and ultimately our culture. ...
among investors, which always occurred during the year before each market crash. When investors closely follow each other's cues, it is easier for panic to take hold and affect the market. This work is a mathematical demonstration of a significant advance warning sign of impending market crashes.


Trading curbs and trading halts

One mitigation strategy has been the introduction of
trading curb A trading curb (typically known as a circuit breaker in Wall Street parlance) is a financial regulatory instrument that is in place to prevent stock market crashes from occurring, and is implemented by the relevant stock exchange organization. Si ...
s, also known as "circuit breakers", which are a
trading halt A trading halt occurs in the U.S. when a stock exchange stops trading on a specific security for a certain time period. The halt, which can happen a few times a day per security if FINRA deems it, usually lasts for one hour, but is not limited ...
in the cash market and the corresponding trading halt in the derivative markets triggered by the halt in the cash market, all of which are affected based on substantial movements in a broad market indicator. Since their inception after Black Monday (1987), trading curbs have been modified to prevent both speculative gains and dramatic losses within a small time frame.


United States

There are three thresholds, which represent different levels of decline in the
S&P 500 Index The Standard and Poor's 500, or simply the S&P 500, is a stock market index tracking the stock performance of 500 large companies listed on stock exchanges in the United States. It is one of the most commonly followed equity indices. As of D ...
: 7% (Level 1), 13% (Level 2), and 20% (Level 3). * If Threshold Level 1 (a 7% drop) is breached before 3:25pm, trading halts for a minimum of 15 minutes. At or after 3:25 pm, trading continues unless there is a Level 3 halt. * If Threshold Level 2 (a 13% drop) is breached before 1 pm, the market closes for two hours. If such a decline occurs between 1 pm and 2 pm, there is a one-hour pause. The market would close for the day if stocks sank to that level after 2 pm * If Threshold Level 3 (a 20% drop) is breached, the market would close for the day, regardless of the time.


France

For the CAC 40 stock market index in France, daily price limits are implemented in cash and derivative markets. Securities traded on the markets are divided into three categories according to the number and volume of daily transactions. Price limits for each security vary by category. For instance, for the most liquid category, when the price movement of a security from the previous day's closing price exceeds 10%, trading is suspended for 15 minutes. If the price then goes up or down by more than 5%, transactions are again suspended for 15 minutes. The 5% threshold may apply once more before transactions are halted for the rest of the day. When such a suspension occurs, transactions on options based on the underlying security are also suspended. Further, when stocks representing more than 35% of the capitalization of the CAC40 Index are halted, the calculation of the CAC40 Index is suspended and the index is replaced by a trend indicator. When stocks representing less than 25% of the capitalization of the CAC40 Index are halted, trading on the derivative markets are suspended for half an hour or one hour, and additional margin deposits are requested.


See also

*
Behavioral finance Behavioral economics studies the effects of psychological, cognitive, emotional, cultural and social factors on the decisions of individuals or institutions, such as how those decisions vary from those implied by classical economic theory. ...
*
Business cycle Business cycles are intervals of expansion followed by recession in economic activity. These changes have implications for the welfare of the broad population as well as for private institutions. Typically business cycles are measured by examin ...
* Economic bubble *
Economic collapse Economic collapse, also called economic meltdown, is any of a broad range of bad economic conditions, ranging from a severe, prolonged depression with high bankruptcy rates and high unemployment (such as the Great Depression of the 1930s), to a ...
*
Financial market A financial market is a market in which people trade financial securities and derivatives at low transaction costs. Some of the securities include stocks and bonds, raw materials and precious metals, which are known in the financial market ...
*
Financial stability Financial stability is a property of a financial system that dissipates financial imbalances that arise endogenously in the financial markets or as a result of significant adverse and unforeseeable circumstances. When stable, the system absorbs ...
*
Financial crisis A financial crisis is any of a broad variety of situations in which some financial assets suddenly lose a large part of their nominal value. In the 19th and early 20th centuries, many financial crises were associated with banking panics, and man ...
*
List of stock market crashes and bear markets This is a list of stock market crashes and bear markets. The difference between the two relies on speed (how fast declines occur) and length (how long they last). Stock market crashes are quick and brief, while bear markets are slow and prolonged. ...
*
Market trend A market trend is a perceived tendency of financial markets to move in a particular direction over time. Analysts classify these trends as ''secular'' for long time-frames, ''primary'' for medium time-frames, and ''secondary'' for short time-fram ...
*
Mass hysteria Mass psychogenic illness (MPI), also called mass sociogenic illness, mass psychogenic disorder, epidemic hysteria, or mass hysteria, involves the spread of illness symptoms through a population where there is no infectious agent responsible for c ...
* Modeling and analysis of financial markets * Stock market bubble * Flash crash


References


Further reading

* * * * * *


External links


Le Bris, David. "What is a market crash?" ''The Economic History Review''
{{Financial crises Business failures