Stocks were giving back the bulk of Wednesday’s epic bounce as volatility on Wall Street continued despite President Donald Trump’s partial climbdown on tariff rates.

The steep selloff was again threatening to put the market’s circuit-breaker rule in play. That dictates that a fall of 7% for the S&P 500 before 3:25 p.m. Eastern time results in a marketwide trading halt for a minimum of 15 minutes. Once trading resumes, a further decline on the day of 13% would spark another 15-minute halt. If the drop then extends to 20%, trading is halted for the rest of the day.

Note, however, that after 3:25 p.m., it takes a 20% drop to halt trading.