2010 Flash Crash Causes

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Written By
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Written By
Dan Buckley
Dan Buckley is an US-based trader, consultant, and part-time writer with a background in macroeconomics and mathematical finance. He trades and writes about a variety of asset classes, including equities, fixed income, commodities, currencies, and interest rates. As a writer, his goal is to explain trading and finance concepts in levels of detail that could appeal to a range of audiences, from novice traders to those with more experienced backgrounds.

The 2010 Flash Crash was a significant market crash that occurred on May 6, 2010.

It was characterized by the rapid decline and recovery of stock and commodity prices over a very short period.


Key Takeaways – 2010 Flash Crash Causes

  • High-Frequency Trading (HFT) Impact
    • Rapid, automated trading by HFT algorithms exacerbated the crash.
    • Demonstrates how technology can accelerate market movements.
  • Liquidity Crisis
    • A sudden withdrawal of liquidity by electronic traders magnified price declines.
    • Highlights the importance of market liquidity.
  • Regulatory Gaps
    • The crash revealed regulatory weaknesses in overseeing automated trading and the need for improved market safeguards.


The causes of the Flash Crash have been extensively studied and can be attributed to a combination of factors:

High-Frequency Trading (HFT)

High-frequency trading had a role.

These algorithms were designed to execute trades at extremely high speeds and in large volumes.

They reacted to market conditions automatically, without human intervention, which led to a rapid escalation of selling pressure.


Interconnected Markets

The interconnectedness of various securities markets (stocks, futures, options) meant that distress in one market quickly spread to others.



The rapid selling led to a temporary liquidity crisis, as the number of sell orders far exceeded the available buy orders, which caused a sharp drop in prices.


Order Flow Toxicity

The imbalance in order flow, where there were more aggressive sell orders than buy orders, made it difficult for liquidity providers to maintain an orderly market.


Large Trader Impact

A significant event that triggered the crash was a large sell order by a mutual fund, identified in reports as Waddell & Reed Financial Inc.

This large order was executed via an automated algorithm that sold a large number of E-Mini S&P 500 futures contracts without regard to price or time.

If a large number of orders are dumped into the market at one time without enough corresponding buy orders, this can cause rapid price falls.


Market Structure & Rules

The market’s structure and rules at the time contributed to its fragility.

For example, different trading venues had inconsistent rules for handling extreme price movements.


Regulatory Gaps

Existing regulations and oversight mechanisms weren’t equipped to handle the new dynamics introduced by high-frequency trading and other technological advances in the markets.


Refinement of Circuit Breakers

Circuit breakers existed in the market before the 2010 Flash Crash, having been implemented after the 1987 stock market crash to prevent severe market downturns.

Market-wide circuit breakers were refined and adjusted after the 2010 Flash Crash to better manage extreme volatility and prevent similar market disruptions in the future.

Pros & Cons of Circuit Breakers

Market-wide circuit breakers have both positive and negative impacts on market dynamics and investor welfare.

Pros of Circuit Breakers

On the positive side, they can stabilize markets by providing a cooling-off period.

This allows for better-informed decision-making and potentially prevents panic selling.

This can help maintain market integrity and investor confidence during turbulent times.

Cons of Circuit Breakers

Nevertheless, the anticipation of a circuit breaker can lead to adverse effects, such as the “magnet effect,” where price volatility increases as the market nears the trigger point.

This can potentially hasten the activation of the circuit breaker.

This period can also see a spike in trading activity and an increase in negative skewness in returns, as traders rush to adjust their positions before the halt.


The overall impact on investor welfare is mixed and depends on the motivations behind investors’ trading actions.

If trading is primarily for risk-sharing purposes, circuit breakers may have a positive effect by preventing market overreactions.

Conversely, if trading is driven by irrational speculation, circuit breakers might not improve welfare and could exacerbate market volatility and inefficiencies.

Like with many things, there are plusses and minuses to circuit breakers and their overall value and effects depend on context and circumstances.



The 2010 Flash Crash highlighted the need for better understanding and regulation of modern financial markets, especially regarding automated trading and high-frequency trading practices.

In response, regulatory bodies like the Securities and Exchange Commission (SEC) and Commodity Futures Trading Commission (CFTC) implemented measures to enhance market stability and resilience.

The most prominent was the adjustment of circuit breakers to temporarily halt trading in response to rapid market declines.

Related Content on Historical Financial Bubbles and Disasters


Article Sources

  • https://www.emerald.com/insight/content/doi/10.1108/JCMS-10-2017-001/full/html
  • https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0196920
  • https://www.elgaronline.com/downloadpdf/edcoll/9781847207562/9781847207562.00022.pdf
  • https://jpm.pm-research.com/content/37/2/118.short
  • https://onlinelibrary.wiley.com/doi/abs/10.1111/jofi.13310?campaign=wolearlyview

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