Market Disruption And US Exchange Developments

The COVID-19 outbreak and the breakdown of negotiations between oil producers each contributed to a fall in the stock market, ending the longest bull market in history and bringing about a period of volatility. As of March 23, 2020, movements in the stock market had led to four 7% declines in the S&P 500 index in 2020, each triggering cross-market circuit breakers and bringing trade to a halt across exchanges (trading halt). The SEC relies on various mechanisms and discretionary powers capable of pausing or stopping the trade of individual securities or general market activity. Fifteen-minute trading halts, for instance, occur automatically when the S&P 500 index declines by 7% and 13% from the prior day's close, and day-long trading halts occur automatically when the S&P 500 index declines by 20% from the prior day's close. There are also automatic mechanisms to limit trading of specific securities during particularly volatile periods, and to prohibit short sales