US stock market: Indexes end sharply higher; AI chip maker Nvidia jumps again after the bell

US stock market:  U.S. stocks ended sharply higher on Wednesday as shares of Nvidia (NVDA.O) gained ahead of quarterly results from the company whose chips are widely used for artificial intelligence (AI) computing. Shares of Nvidia, which reported results after the closing bell, jumped 9 per cent, extending a gain of 3.2 per cent during the regular session. It forecast third-quarter revenue above Wall Street targets. Other tech companies jumped in after-hours trading as well including Microsoft (MSFT.O), which was last up about 2 per cent.

Bullish investors have been hopeful that upbeat news from Nvidia could could further ear's strong rally in tech stocks. Including the session move, Nvidia's stock is up more than 220 per cent for the year so far. "Not just their numbers, but what they say in the conference call about what's happening in AI is going to have a big impact on market sentiment," said Rick Meckler, partner, Cherry Lane Investments, a family investment office in New Vernon, New Jersey.

Nvidia is part of the so-called Magnificent Seven group of megacap stocks including Apple (AAPL.O) and Tesla (TSLA.O) that have powered the S&P 500's sharp gains this year. During the trading session, stock investors were encouraged as the yield on the 10-year U.S. Treasury note eased from near 16-year highs after weak business activity data from the United States and the euro zone.

U.S. Federal Reserve Chair Jerome Powell's comments on Friday at the Jackson Hole conference will be scrutinized for clues on the U.S. central bank's interest rate path. The Dow Jones Industrial Average (.DJI) rose 184.15 points, or 0.54 per cent, to 34,472.98, the S&P 500 (.SPX) gained 48.46 points, or 1.10 per cent, to 4,436.01 and the Nasdaq Composite (.IXIC) added 215.16 points, or 1.59 per cent, to 13,721.03. Before the PMI data, yields on the 10-year note had been rising this month as investors were thinking the Fed could keep rates higher for longer.

According to strategists in a Reuters poll, the S&P 500 will eke out only marginal gains between now and year end, after its strong move up already this year. The index was forecast to end the year at 4,496. Shares of drugmaker Gilead Sciences (GILD.O) rose 0.9 per cent and Merck & Co (MRK.N) advanced 3.8 per cent after Swiss rival Roche (ROG.S) inadvertently published positive lung cancer drug trial data.

Advancing issues outnumbered declining ones on the NYSE by a 3.74-to-1 ratio; on Nasdaq, a 2.07-to-1 ratio favored advancers. The S&P 500 posted 8 new 52-week highs and 10 new lows; the Nasdaq Composite recorded 46 new highs and 156 new lows.