The 2010 Flash Crash: A 1,000-Point Drop in 36 Minutes
What Happened on May 6, 2010?
Markets were already nervous that day. The European debt crisis was escalating, with Greece on the verge of default. The S&P 500 was down about 4% when, at approximately 2:32 PM Eastern, selling pressure suddenly intensified.
Within minutes, prices went into free fall. The DJIA dropped from roughly 10,500 to below 9,900. Some individual stocks traded at absurd prices — Accenture briefly hit one cent, while Apple traded at $100,000. About 20,000 trades were executed at prices more than 60% away from their pre-crash values.
By 3:07 PM — roughly 36 minutes after the crash began — the market had recovered most of its losses. The DJIA closed down 348 points (3.2%), masking the chaos that had occurred intraday.
What Caused the Flash Crash?
A large sell order. A Kansas City mutual fund company, Waddell & Reed, used an automated algorithm to sell $4.1 billion worth of E-Mini S&P 500 futures contracts. The algorithm was set to execute based on volume without regard to price or time — dumping contracts regardless of market conditions.
High-frequency trading (HFT) amplification. HFT firms initially absorbed the selling but then began rapidly buying and reselling the same contracts among themselves — a “hot potato” effect that created volume without real liquidity. When HFT firms recognized the abnormal pattern, many pulled out entirely, evaporating the order book.
Liquidity vacuum. As prices fell, market makers and HFT firms withdrew their bids. This created a cascading collapse: with no buyers, sell orders hit lower and lower prices, triggering stop-loss orders and more automated selling.
Cross-market contagion. The futures market decline spilled into equities, ETFs, and options. The fragmented market structure — with dozens of exchanges and dark pools — made it impossible to coordinate a response in real time.
Timeline of the Crash
| Time (ET) | Event | Impact |
|---|---|---|
| Before 2:00 PM | Markets declining on European debt fears | S&P 500 down ~4% |
| 2:32 PM | Waddell & Reed algorithm begins massive futures sell | Selling pressure accelerates sharply |
| 2:41 PM | HFT firms begin withdrawing from market | Liquidity evaporates; bid-ask spreads explode |
| 2:45 PM | DJIA reaches intraday low (−998 points) | Individual stocks trading at $0.01 or $100,000 |
| 2:45 PM | CME pauses E-Mini trading for 5 seconds | Brief halt allows some stabilization |
| 3:00 PM | Markets begin recovering | Automated buying and bargain hunters enter |
| 4:00 PM | Market closes | DJIA down 348 points (3.2%) — most losses recovered |
Regulatory Response
Single-stock circuit breakers. The SEC implemented Limit Up-Limit Down (LULD) rules that pause trading in individual stocks when prices move beyond specified percentage bands. This prevents the absurd penny-stock trades that occurred during the flash crash.
Consolidated audit trail. Regulators pushed for better tracking of orders across fragmented markets, though implementation took years.
Navinder Sarao prosecution. In 2015, a London-based trader named Navinder Sarao was charged with “spoofing” — placing and then rapidly canceling large orders to manipulate prices. His activity contributed to but didn’t solely cause the crash. He was sentenced in 2020.
Flash Crash vs. Black Monday 1987
| Factor | 2010 Flash Crash | Black Monday 1987 |
|---|---|---|
| Duration | ~36 minutes | Full trading day |
| Max decline | −9% intraday (recovered) | −22.6% at close |
| Cause | Algorithmic selling + HFT withdrawal | Portfolio insurance + program trading |
| Recovery | Same day (mostly) | ~2 years |
| Common theme | Automated trading creating self-reinforcing selling cascades that overwhelm human decision-making | |
Key Takeaways
- The 2010 flash crash saw the DJIA plunge ~998 points in 36 minutes before recovering — exposing critical fragility in electronic markets.
- A single large algorithmic sell order, combined with HFT firms withdrawing liquidity, created a cascading price collapse.
- Individual stocks traded at absurd prices ($0.01 and $100,000), and over 20,000 trades were later canceled as “clearly erroneous.”
- The crash led to Limit Up-Limit Down circuit breakers for individual stocks and increased scrutiny of high-frequency trading.
- The core lesson: electronic market liquidity can vanish in seconds, and the apparent depth of an order book doesn’t guarantee you can execute at reasonable prices during stress.
Frequently Asked Questions
What was the 2010 flash crash?
The 2010 flash crash occurred on May 6, 2010, when the DJIA dropped approximately 998 points (about 9%) in roughly 36 minutes before recovering most of the decline by the market close. It was triggered by a large algorithmic sell order and amplified by the withdrawal of high-frequency traders.
How long did the flash crash last?
The crash itself lasted approximately 36 minutes, from about 2:32 PM to 3:07 PM Eastern. The DJIA reached its intraday low around 2:45 PM. Most of the decline was recovered by the 4:00 PM close, making it one of the shortest and most dramatic market events in history.
What caused the 2010 flash crash?
The primary trigger was a $4.1 billion automated sell order in E-Mini S&P 500 futures by Waddell & Reed. This overwhelmed available liquidity, caused high-frequency trading firms to withdraw their bids, and created a cascading price decline across stocks, ETFs, and derivatives.
What are flash crashes?
A flash crash is an extremely rapid, deep decline in security prices followed by a quick recovery, typically occurring within minutes. They are usually caused by algorithmic trading, liquidity withdrawal, or technical glitches rather than fundamental economic changes. Several mini flash crashes have occurred since 2010 in various markets.
What regulations changed after the flash crash?
The SEC implemented Limit Up-Limit Down (LULD) circuit breakers for individual stocks, which pause trading when prices move beyond set percentage bands. The exchanges also improved coordination protocols and began developing a consolidated audit trail to track orders across fragmented markets.