Stocks across Europe finished higher Wednesday as investors took on risk after five straight days of losses and ahead of the Federal Reserve's monetary-policy decision.

The search for safety has been driven in part by a series of opinion polls showing support for a "Brexit" in the June 23 referendum on whether the U.K. should leave the European Union.

U.S. stocks relinquished modest gains and closed lower on Wednesday, stretching a losing streak to five days, as investors weighed the Federal Reserve's decision to delay rate increases.

The Fed acknowledged that hiring slowed and that business fixed investment was soft and signaled a slower approach on raising borrowing costs.

Asian stocks turned lower on Thursday and the yen surged after the Bank of Japan refrained from taking further stimulus steps, hours after the Federal Reserve's own review had struck a cautious note on its policy outlook.

The BOJ kept monetary policy steady and stuck to its optimistic view of the economy on Thursday, even as renewed yen rises and slumping stock prices threaten to derail a fragile economic recovery.

While the BOJ's decision did not come as a big surprise, expectations that the central bank will take action next month increased. But for now uncertainty over whether Britain will vote to quit the European Union is strengthening the yen because of the Japanese currency's safe-haven status.