Wall Street romped to records Thursday as a delayed jubilation swept markets worldwide following the Federal Reserve’s big cut to interest rates. The S&P 500 jumped 1.7% for one of its best days of the year and topped its last all-time high set in July.

Just as Wall Street traders come to grips with the Federal Reserve’s interest-rate cut, Friday’s US options expiration threatens to whipsaw the market some more.

The Federal Reserve's closely followed overnight reverse-repo facility already has begun to reflect Wednesday's big interest-rate cut. Wall Street firms rushed to park extra cash overnight at the facility in the wake of the pandemic,