(Updates with index/price moves, macroeconomic data, and geopolitical news from the first paragraph.)

US equity indexes rose as government bond yields slumped after the Federal Reserve reaffirmed its commitment to taming inflation while tightening policy, and as crude oil prices fell.

The Nasdaq Composite jumped 1.6% to 26,384.5, the S&P 500 climbed 1.1% to 7,632.8, and the Dow Jones Industrial Average advanced 0.7% to 51,802.1 after midday Thursday.

The US Federal Reserve raised its benchmark lending rate by 25 basis points in a unanimous vote on Wednesday to combat sticky inflation, while signaling another hike later this year. The Federal Open Market Committee lifted the fed funds rate to 3.75% to 4%, the first time it has tightened monetary policy since July 2023.

"After more than five years of significantly elevated inflation, a period which included a rate cutting cycle, the new Warsh Fed appears to be taking a step in the right direction to combat dangerously high price pressures," Lindsey Piegza, Stifel chief economist, said in a note.

US Treasury yields retreated after midday. The 10-year yield fell 5.3 basis points to 4.95%. The two-year yield slid 3.7 basis points to 4.69%.

Meanwhile, China has privately asked Tehran to help rein in Yemen's Houthis after an appeal to Beijing by Saudi Arabia following the Iran-backed group's military blitz in the past week, three Iranian sources familiar with the matter told Reuters. Riyadh turned to China for help after the Houthis made rapid advances along the Red Sea coast and around the Bab el-Mandeb Strait, moves that have left Saudi oil exports and shipping more exposed, the sources told the news agency.

The front-month US West Texas Intermediate crude oil contract dropped 0.2% to $102.22 per barrel, and the global benchmark North Sea Brent fell 1.1% to $104.70 per barrel.

In the week ended Sept. 12, 196,000 people filed for unemployment insurance, down 10,000 from the prior week. The consensus was 207,000, according to a Jefferies note. This is the lowest initial claims print since the week ended July 18. The four-week moving average fell to 203,250 from 206,000.

In company news, Generac (GNRC) soared 19%, the S&P 500's top gainer, a day after signing a long-term supply deal with Amazon (AMZN) to provide backup power generators. Canaccord Genuity adjusted its price target on Generac to $375 from $275 while keeping its buy rating.

HSBC downgraded Copart (CPRT) to a hold rating from buy, while adjusting its price target to $36 from $46. Copart traded 3.8% lower, one of the worst performers on Nasdaq.