The S&P 500 ended lower on Tuesday as the index was unable to bounce from a sharp sell-off in the prior session with a key policy statement from the Federal Reserve on deck that will reveal how aggressive the central bank's policy path will be.

Analyst expectations had largely been predicting the Fed would hike by 50 basis points at the conclusion of its meeting on Wednesday.

However, views that a 75 basis point hike was on the table have been growing after Friday's higher-than-expected consumer price index (CPI) data for May. In addition, a report from the Wall Street Journal on Monday and forecasts from several banks, including JP Morgan and Goldman Sachs, signaling a 75 basis point hike have bolstered that belief.

Traders are currently pricing in a more than 90 percent chance of a 75 basis point hike, up from 3.9 percent a week ago, according to CME's FedWatch Tool.

"Ultimately, even though we are seeing even more red and more negative pressure here, in general today we believe is really a wait-and-see day," said Greg Bassuk, CEO at AXS Investments in Port Chester, New York.

The Dow Jones Industrial Average fell 0.5 percent, to 30,365, the S&P 500 lost 0.38 percent, to 3,735 and the Nasdaq Composite added 0.18 percent, to 10,828.

The benchmark S&P 500 suffered its fifth straight daily decline, marking its longest losing streak since early January. Monday's declines put the index down more than 20 percent from its most recent record high, confirming a bear market began on January 3, according to a commonly used definition.

FedEx Corp surged 14.41 percent after raising its quarterly dividend by more than 50 percent, while Oracle Corp gained 10.41 percent after posting upbeat quarterly results on demand for its cloud products. (Reuters)