U.S. stock market crash lasting 36 minutes in May 6, 2010
The May 6, 2010, flash crash, also known as the crash of 2:45 or simply the flash crash, was a United States trillion-dollar flash crash (a type of stock market crash) which started at 2:32 p.m. EDT and lasted for approximately 36 minutes.
Overview.
Stock indices, such as the S&amp;P 500, Dow Jones Industrial Average and Nasdaq Composite, collapsed and rebounded very rapidly. The Dow Jones Industrial Average had its second biggest intraday point decline (from the opening) up to that point, plunging 998.5 points (about 9%), most within minutes, only to recover a large part of the loss. It was also the second-largest intraday point swing (difference between intraday high and intraday low) up to that point, at 1,010.14 points. The prices of stocks, stock index futures, options and exchange-traded funds (ETFs) were volatile, thus trading volume spiked. A CFTC 2014 report described it as one of the most turbulent periods in the history of financial markets.
New regulations put in place following the 2010 flash crash proved to be inadequate to protect investors in the August 24, 2015, flash crash — "when the price of many ETFs appeared to come unhinged from their underlying value" — and ETFs were subsequently put under greater scrutiny by regulators and investors.
On April 21, 2015, nearly five years after the incident, the U.S. Department of Justice laid 22 criminal counts, including fraud and market manipulation against Navinder Singh Sarao, a British Indian financial trader. Among the charges included was the use of spoofing algorithms; just prior to the flash crash, he placed orders for thousands of E-mini S&amp;P 500 stock index futures contracts which he planned on canceling later. These orders amounting to about "$200 million worth of bets that the market would fall" were "replaced or modified 19,000 times" before they were canceled. Spoofing, layering, and front running are now banned.
The Commodity Futures Trading Commission (CFTC) investigation concluded that Sarao "was at least significantly responsible for the order imbalances" in the derivatives market which affected stock markets and exacerbated the flash crash. Sarao began his alleged market manipulation in 2009 with commercially available trading software whose code he modified "so he could rapidly place and cancel orders automatically". "Traders Magazine" journalist, John Bates, argued that blaming a 36-year-old small-time trader who worked from his parents' modest stucco house in suburban west London for sparking a trillion-dollar stock market crash is "a little bit like blaming lightning for starting a fire" and that the investigation was lengthened because regulators used "bicycles to try and catch Ferraris". Furthermore, he concluded that by April 2015, traders can still manipulate and impact markets in spite of regulators and banks' new, improved monitoring of automated trade systems.
In May 2014, a CFTC report concluded that high-frequency traders "did not cause the Flash Crash, but contributed to it by demanding immediacy ahead of other market participants".
Some recent peer-reviewed research shows that flash crashes are not isolated occurrences, but have occurred quite often. Gao and Mizrach studied US equities over the period of 1993–2011. They show that breakdowns in market quality (such as flash crashes) have occurred in every year they examined and that, apart from the financial crisis, such problems have declined since the introduction of Reg NMS. They also show that 2010, while infamous for the flash crash, was not a year with an inordinate number of breakdowns in market quality.
Background.
On May 6, 2010, U.S. stock markets opened and the Dow was down, and trended that way for most of the day on worries about the debt crisis in Greece. At 2:42 p.m., with the Dow down more than 300 points for the day, the equity market began to fall rapidly, dropping an additional 600 points in 5 minutes for a loss of nearly 1,000 points for the day by 2:47 p.m. Twenty minutes later, by 3:07 p.m., the market had regained most of the 600-point drop. At the time of the flash crash, in May 2010, high-frequency traders were taking advantage of unintended consequences of the consolidation of the U.S. financial regulations into Regulation NMS, designed to modernize and strengthen the United States National Market System for equity securities. The Reg NMS, promulgated and described by the United States Securities and Exchange Commission, was intended to assure that investors received the best price executions for their orders by encouraging competition in the marketplace, but created attractive new opportunities for high-frequency-traders. Activities such as spoofing, layering and front running were banned by 2015. This rule was designed to give investors the best possible price when dealing in stocks, even if that price was not on the exchange that received the order.
Explanation.
Early theories.
At first, while the regulatory agencies and the United States Congress announced investigations into the crash, no specific reason for the 600-point plunge was identified. Investigators focused on a number of possible causes, including a confluence of computer-automated trades, or possibly an error by human traders. By the first weekend, regulators had discounted the possibility of trader error and focused on automated trades conducted on exchanges other than the NYSE. However, CME Group, a large futures exchange, stated that, insofar as stock index futures traded on CME Group were concerned, its investigation found no evidence for this, or that high-frequency trading played a role, and in fact concluded that automated trading had contributed to market stability during the period of the crash. Others speculate that an intermarket sweep order may have played a role in triggering the crash.
Several plausible theories were put forward to explain the plunge.
SEC/CFTC report.
On September 30, 2010, after almost five months of investigations led by Gregg E. Berman, the U.S. Securities and Exchange Commission (SEC) and the Commodity Futures Trading Commission (CFTC) issued a joint report titled "Findings Regarding the Market Events of May 6, 2010" identifying the sequence of events leading to the flash crash.
The joint 2010 report "portrayed a market so fragmented and fragile that a single large trade could send stocks into a sudden spiral", and detailed how a large mutual fund firm selling an unusually large number of E-Mini S&amp;P contracts first exhausted available buyers, and then how high-frequency traders (HFT) started aggressively selling, accelerating the effect of the mutual fund's selling and contributing to the sharp price declines that day.
The SEC and CFTC joint 2010 report itself says that "May 6 started as an unusually turbulent day for the markets" and that by the early afternoon "broadly negative market sentiment was already affecting an increase in the price volatility of some individual securities". At 2:32 p.m. (EDT), against a "backdrop of unusually high volatility and thinning liquidity" that day, a large fundamental trader (known to be Waddell &amp; Reed Financial Inc.) "initiated a sell program to sell a total of 75,000 E-Mini S&amp;P contracts (valued at approximately $4.1 billion) as a hedge to an existing equity position". The report says that this was an unusually large position and that the computer algorithm the trader used to trade the position was set to "target an execution rate set to 9% of the trading volume calculated over the previous minute, but without regard to price or time".
As the large seller's trades were executed in the futures market, buyers included high-frequency trading firms—trading firms that specialize in high-speed trading and rarely hold on to any given position for very long—and within minutes these high-frequency trading firms started trying to sell the long futures contracts they had just picked up from the mutual fund. "The Wall Street Journal" quoted the joint report, "'HFTs [then] began to quickly buy and then resell contracts to each other—generating a 'hot-potato' volume effect as the same positions were passed rapidly back and forth.'" The combined sales by the large seller and high-frequency firms quickly drove "the E-Mini price down 3% in just four minutes".
From the SEC/CFTC report:
 ;templatestyles src="Template:Blockquote/styles.css" / ;The combined selling pressure from the sell algorithm, HFTs, and other traders drove the price of the E-Mini S&amp;P 500 down approximately 3% in just four minutes from the beginning of 2:41 p.m. through the end of 2:44 p.m. During this same time cross-market arbitrageurs who did buy the E-Mini S&amp;P 500, simultaneously sold equivalent amounts in the equities markets, driving the price of SPY (an exchange-traded fund which represents the S&amp;P 500 index) also down approximately 3%.
Still lacking sufficient demand from fundamental buyers or cross-market arbitrageurs, HFTs began to quickly buy and then resell contracts to each other—generating a “hot-potato” volume effect as the same positions were rapidly passed back and forth. Between 2:45:13 and 2:45:27, HFTs traded over 27,000 contracts, which accounted for about 49 percent of the total trading volume, while buying only about 200 additional contracts net.
As prices in the futures market fell, there was a spillover into the equities markets. The computer systems used by most high-frequency trading firms to keep track of market activity decided to pause trading, and those firms then scaled back their trading or withdrew from the markets altogether.
"The New York Times" then noted, "Automatic computerized traders on the stock market shut down as they detected the sharp rise in buying and selling". As computerized high-frequency traders exited the stock market, the resulting lack of liquidity "caused shares of some prominent companies like Procter &amp; Gamble and Accenture to trade down as low as a penny or as high as $100,000". These extreme prices also resulted from "market internalizers", firms that usually trade with customer orders from their own inventory instead of sending those orders to exchanges, "routing 'most, if not all,' retail orders to the public markets—a flood of unusual selling pressure that sucked up more dwindling liquidity".
While some firms exited the market, firms that remained in the market exacerbated price declines because they "'escalated their aggressive selling' during the downdraft". High-frequency firms during the crisis, like other firms, were net sellers, contributing to the crash.
The joint report continued: "At 2:45:28 p.m., trading on the E-Mini was paused for five seconds when the Chicago Mercantile Exchange ('CME') Stop Logic Functionality was triggered in order to prevent a cascade of further price declines. In that short period of time, sell-side pressure in the E-Mini was partly alleviated and buy-side interest increased. When trading resumed at 2:45:33 p.m., prices stabilized and shortly thereafter, the E-Mini began to recover, followed by the SPY". After a short while, as market participants had "time to react and verify the integrity of their data and systems, buy-side and sell-side interest returned and an orderly price discovery process began to function", and by 3:00 p.m., most stocks "had reverted back to trading at prices reflecting true consensus values".
Criticism of the SEC/CFTC report.
A few hours after the release of the 104-page SEC/CFTC 2010 report, a number of critics stated that blaming a single order (from "Waddell &amp; Reed") for triggering the event was disingenuous. Most prominent of all, the CME issued, within 24 hours, a rare press release in which it argued against the SEC/CFTC explanation:
 ;templatestyles src="Template:Blockquote/styles.css" / ;Futures and options markets are hedging and risk transfer markets. The report references a series of bona fide hedging transactions, totaling 75,000 contracts, entered into by an institutional asset manager to hedge a portion of the risk in its $75 billion investment portfolio in response to global economic events and the fundamentally deteriorating market conditions that day. The 75,000 contracts represented 1.3% of the total E-Mini S&amp;P 500 volume of 5.7 million contracts on May 6 and less than 9% of the volume during the time period in which the orders were executed. The prevailing market sentiment was evident well before these orders were placed, and the orders, as well as the manner in which they were entered, were both legitimate and consistent with market practices. These hedging orders were entered in relatively small quantities and in a manner designed to dynamically adapt to market liquidity by participating in a target percentage of 9% of the volume executed in the market. As a result of the significant volumes traded in the market, the hedge was completed in approximately twenty minutes, with more than half of the participant's volume executed as the market rallied—not as the market declined. Additionally, the aggregate size of this participant's orders was not known to other market participants.
Additionally, the most precipitous