US Stock Futures Tumble on Brexit to Trigger Limit-Down Curbs

U.S. stock futures plunged, triggering a trading curb, as the U.K.’s decision to leave the European Union fanned speculation that a divided Europe would put another brake on already fragile global growth.

S&P 500 Index contracts slumped 5.1 percent at 12:28 a.m. in New York, triggering a limit-down rule. The curb means the contract cannot trade at a lower price for the remainder of the overnight session. The pound slid the most on record to its weakest since 1985, while the yen rallied on demand for haven assets. Polling before the referendum had indicated a vote too close to call. At 5:11 a.m. London time, BBC projections showed voters backing “Leave” by 52 percent to 48 percent.