Wall Street is back in rally mode, with investors seizing on the latest sign that interest rates could begin to come down this year.

The S&P 500 rose 0.8 percent on Wednesday morning, adding to three straight weeks of gains and pushing it above its previous record, set on March 28.

It marks a sharp shift from the sour mood that helped pull the index more than 5 percent lower at the beginning of April, as investors got used to the idea that high interest rates might stick around for longer, weighing on the economy and the markets.

Fresh inflation data on Wednesday morning provided the catalyst for the index to cross through its previous record. The S&P 500 is up more than 6 percent since its most recent low in April.

Wednesday’s report, data from the closely watched Consumer Price Index, showed a modest slowdown in the pace of rising prices, in line with economists’ expectations. Investors welcomed the numbers and a return to the trend of gradually receding inflation after months of disappointing data that had upset financial markets and sent stock prices lower.

“This is the first good C.P.I. report in four months and the market likes it,” said Gary Pzegeo, head of fixed income at CIBC Private Wealth US.