Decades of little-noticed efforts to build guardrails for wild market moves got a rare workout last week when circuit breakers halted trading in all US stocks for the first time since 1997.
Were they effective? The jury is still out.
Trading
Wall Street traders question the value of stock market circuit breakers
The mechanism, which some complain does little good, was triggered twice last week during a coronavirus-fueled selloff, offering traders a breather
