As volatility within global equity markets has spiked, the discussion about exchange circuit breakers has taken center stage. Nevertheless, exchanges have to be careful about how tight those breakers are, Nasdaq CEO Bob Greifeld said Tuesday.
"As we went on yesterday, we asked ourselves if our breakers are tight enough," Greifeld said in a CNBC "Squawk Box" interview. "But the philosophical argument is, you want the circuit breaker to be the pause that refreshes, but you don't want the circuit breaker to prevent somebody from buying or selling."
Greifeld added that this is actually one of the main problems with the Chinese stock market. "They've put in these absolute breakers where you can't sell when you want to, and that's going to have a negative long-term impact," he said.
China's benchmark Shanghai composite plunged another 7.6 percent Tuesday, a day after falling more than 8 percent and leading world equities down.