A flash crash is a very rapid, deep, and volatile fall in security prices occurring within an extremely short time period. A flash crash frequently stems from trades executed by black-box trading, combined with high-frequency trading, whose speed and interconnectedness can result in the loss and recovery of billions of dollars in a matter of minutes and seconds.
On June 22, 2017, the price of Ethereum, the second-largest digital cryptocurrency, dropped from more than $300 to as low as $0.10 in minutes at GDAX exchange. Suspected for market manipulation or an account takeover at first, later investigation by GDAX claimed no indication of wrongdoing. The crash was triggered by a multimillion-dollar selling order which brought the price down, from $317.81 to $224.48, and caused the following flood of 800 stop-loss and margin funding liquidation orders, crashing the market.
On October 7, 2016, there was a flash crash in the value of sterling, which dropped more than 6% in two minutes against the US dollar. It was the pound's lowest level against the dollar since May 1985. The pound recovered much of its value in the next few minutes, but ended down on the day's trading, most likely due to market concerns about the impact of a "hard Brexit"—a more complete break with the European Union following Britain's 'Leave' referendum vote in June. It was initially speculated that the flash crash may have been due to a fat-finger trader error or an algorithm reacting to negative news articles about the British Government's European policy.
USDJPY and AUDUSD flash crash
On January 2, 2019, a flash crash was seen in the value USDJPY and AUDUSD, which dropped more than 4% in a few minutes. It was the USD lowest level against the Yen and AUD against USD since March 2009. The USDJPY and AUDUSD recovered much of its value in the next few minutes. It was speculated that the flash crash may have been due to Apple reporting reduced sales forecast in China but this seems unlikely as the report came out an hour before the actual crash. The lows reported on USDJPY also varied with Reuters reporting a low of 104.90 on USDJPY while FXMarketAPI reported a low of 104.45.
Other crashes
In October 2013, a flash crash occurred on the Singapore Exchange which wiped out $6.9 billion in capitalization and saw some stocks lose up to 87 percent of their value. The crash resulted in new regulations being announced in August 2014. Minimum trading prices of 0.20 cents per share would be introduced, short positions would be required to be reported, and a 5 percentcollaterallevy implemented. The exchange said the measures were to curb excessive speculation and potential share price manipulation. Two short-lived movements in several stock prices followed by recovery were reported for November 25, 2014.
Significance of recovery
Events described as flash crashes typically exhibit a rapid partial or total price recovery. Conversely, rapid price falls in response to adverse news which do not rapidly revert are not generally characterized as flash crashes.
