Which U.S. stock exchange was the first to install a computerized circuit-breaker system after the 1987 crash?

The New York Stock Exchange was the first U.S. stock exchange to install a computerized circuit-breaker system after the 1987 crash.

The 1987 collapse exposed how quickly selling could spread through interconnected markets and automated trading systems. In response, U.S. regulators and exchanges developed coordinated mechanisms that could pause trading after exceptionally large index declines. The New York Stock Exchange implemented its system in 1988.

These pauses were designed to slow panic and give investors, brokers, and regulators time to assess information. They did not guarantee that prices would recover, and they were not intended to prevent ordinary volatility. Instead, the goal was to interrupt disorderly trading and improve communication during extreme moves.

Modern U.S. market-wide circuit breakers are based on percentage declines in the S&P 500 rather than only on Dow point changes. Separate rules can also pause trading in individual securities. The post-1987 system has therefore evolved substantially from its original form.