Which trading system was blamed for amplifying selling during the 2010 Flash Crash?

High-frequency trading was blamed for amplifying selling during the 2010 Flash Crash.

High-frequency trading, or HFT, was identified by investigators as an important factor in the market disruption on May 6, 2010. Automated firms rapidly placed and canceled orders, and liquidity became unstable as selling pressure moved through futures and equity markets. The Dow briefly fell about 1,000 points before recovering much of the loss.

The official investigations did not conclude that one HFT firm alone caused the event. A large sell order in E-mini S&P 500 futures interacted with automated trading and fragmented market structure. The episode showed how quickly algorithmic strategies can affect prices when normal liquidity disappears.

HFT is often confused with algorithmic trading in general. Algorithmic trading is the broader category of computer-directed order execution; high-frequency trading is a particular approach characterized by very rapid decisions, high message volumes, and short holding periods. The Flash Crash led to new safeguards and market-structure reviews.