NEW YORK: The S&P 500 and Nasdaq scored their biggest daily percentage gains since Feb. 22 and the Dow rose on Wednesday as chip stocks rallied and the Federal Reserve kept US interest rates unchanged while signaling possible easing in September if inflation cools.

Seven out of the 11 S&P 500 sectors advanced, led by technology and consumer discretionary stocks. Healthcare, real estate and consumer staples were the weakest.

The Fed kept its benchmark overnight interest rate in the 5.25%-5.50% range as it ended its two-day policymaking meeting on Wednesday, but opened the door to easing in September, seven weeks shy of the November US elections. The benchmark US 10-year note yield fell 9.8 basis points to 4.043%.

The Dow Jones Industrial Average rose 0.24% to 40,842.79, the S&P 500 gained 1.58% to 5,522.30 and the Nasdaq Composite advanced 2.64% to 17,599.40.

"It was the worst kept secret on the planet that the Fed was not going to cut in July," said Jake Dollarhide, chief executive of Longbow Asset Management in Tulsa, Oklahoma. "The Fed is going to have its day in the sun in September with a 25 or 50 basis point cut, but I would not be surprised if that is already priced into stocks."

During his press conference, Fed chair Jerome Powell said policymakers discussed the case for cutting rates, but a "strong majority" agreed that now was not the appropriate time.

"The statement didn't move the needle at all," said Mark Malek, chief investment officer at Siebert Next in New York, referring to the Fed's official statement. "But listening to him speak, it's clear they're all locked and loaded for September rate cut and they're going to maintain their optionality."

Data released early Wednesday showed July US private payrolls increased far less than expected, indicating an easing in persistent labor market tightness.

For the month, the S&P 500 climbed 1.1%, the Dow jumped 4.4%, while the Nasdaq lost 0.8%.

Nvidia jumped nearly 13%, helped by a rosy 2024 sales forecast for artificial intelligence chips by peer Advanced Micro Devices, whose shares also gained 4.3%. The Philadelphia SE Semiconductor index rose finished up nearly 7%.

US President Joe Biden's administration plans to unveil a new rule next month that will expand US powers to stop exports of semiconductor manufacturing equipment from some foreign countries to Chinese chipmakers, two sources familiar with the matter told Reuters.

Microsoft dipped 1% after it posted massive AI-related expenses. Meta jumped 5% after the bell as its earnings beat market expectations. Apple and Amazon.com , which will report earnings on Thursday, closed up 1.5% and 2.9%, respectively.

Advancing issues outnumbered decliners by a 2.23-to-1 ratio on the NYSE. On the Nasdaq, 2,603 stocks rose and 1,648 fell as advancing issues outnumbered decliners by 1.58-to-1.

The S&P 500 posted 68 new 52-week highs and one new low while the Nasdaq Composite recorded 168 new highs and 104 new lows.

Total volume on US exchanges was 13.3 billion, compared with the 20-day moving average of 13.27 billion.

 - Reuters