Which futures contract was central to U.S. charges linked to the 2010 Flash Crash?

The futures contract central to U.S. charges linked to the 2010 Flash Crash was the E-mini S&P 500 futures contract.

The E-mini is an electronically traded futures contract whose value is tied to the S&P 500 Index. Introduced by CME in 1997, it became one of the world’s most heavily traded stock-index futures, allowing institutions and traders to hedge or speculate with less capital than a full-size S&P 500 contract.

On May 6, 2010, the E-mini market was at the center of a rapid cascade. A large automated sell program placed orders for 75,000 contracts, valued at about $4.1 billion, while liquidity was already thin. High-frequency trading firms rapidly bought and resold contracts, intensifying the price drop before the shock spread into stocks and exchange-traded funds.

The contract also appeared in criminal charges against trader Navinder Singh Sarao. Prosecutors alleged that he used spoofing orders in E-mini futures, placing large orders he intended to cancel. The charges concerned alleged market manipulation, not proof that one trader alone caused every aspect of the crash.