U.S. stocks advanced amid a global rally, with the S&P 500 Index posting its strongest two-day climb in four months, as tension eased over the impact of a U.K. exit from the European Union.

Fears that Britain's EU withdrawal will further stymie global growth continued to ebb, soothed by speculation policy makers will counter the effects. Energy shares capped their best two days since March as crude jumped. A Goldman Sachs Group Inc. basket of the most shorted shares in the Russell 3000 Index saw its biggest surge since 2009, while the Dow Jones Industrial Average stretched its rebound to more than 550 points since Monday's close.

With Britain in limbo as EU leaders gathered in Brussels to discuss the nation's withdrawal from the bloc, traders have pushed back bets on Federal Reserve interest-rate increases, indicating higher borrowing costs are unlikely before 2018. Meanwhile, a majority of economists surveyed by Bloomberg predict that the Bank of England will add more stimulus, including cutting rates in the third quarter.

Equities are recovering for a second session after two days of heavy selling sparked by the Brexit decision last week wiped $3.6 trillion from global equities. The S&P 500 had tumbled 5.3 percent to briefly erase its 2016 advance, and has since cut its post-vote drop by more than half. The CBOE Volatility Index tumbled for a third day, the longest in two weeks.

Investors are looking to policy makers for support as they await Britain's plan for its extrication from the EU. While European Central Bank President Mario Draghi called for global policy alignment, South Korea announced a fiscal stimulus package on Tuesday and Bank of Japan Chief Haruhiko Kuroda said Wednesday that more funds can be injected into the market should they be needed.

The turmoil spurred by the U.K. vote interrupted the S&P 500's march toward an all-time high this month, a move stoked by optimism that a mixture of low rates and moderate growth would bolster rising stock prices. The benchmark came within 1 percent of a record on June 8 and again last Thursday, on the day of the referendum as investors wagered Britain would remain in the EU. The gauge is now on track for its first monthly decline since February.