Midday movers: Affirm, Gap, Marvell Technology and more

Investing.com -- U.S. stocks were rising after Federal Reserve Chair Jerome Powell told the gathering in Jackson Hole, Wyo., that inflation is still too high and the central bank was prepared to continue raising rates to combat it.

Here are some of the biggest U.S. stock movers today:

• Affirm (NASDAQ:AFRM) stock rose over 29% after the buy now, pay later fintech beat expectations on revenue and raised its guidance, boosted by a jump in transactions on its platforms.

• Gap (NYSE:GPS) stock rose 4.5% after the casual clothing retailer beat quarterly profit expectations but missed slightly on revenue expectations, with comparable store sales down 6% over its brands.

• Marvell Technology (NASDAQ:MRVL) stock fell 7.3% after the chipmaker posted a fall in second quarter revenue, hit by a weak enterprise market.

• Nordstrom (NYSE:JWN) stock fell 9.1% after the luxury department store chain adopted a cautious tone over demand in the second half of the year, warning of higher credit losses as more consumers default on payments.

• Hawaiian Electric (NYSE:HE) stock slumped over 16% after the utility suspended its dividend, while S&P GIobal downgraded its credit rating deeper into "junk" territory amid scrutiny over its role in the Maui wildfires.

• AstraZeneca (NASDAQ:AZN) ADRs rose 0.3% after the drugmaker filed a legal challenge to critical aspects of a program that gives the Medicare health insurance plan the power to negotiate lower drug prices.

• Netflix (NASDAQ:NFLX) stock rose 1.7% after Loop Capital upgraded the streaming giant to ‘buy’ from ‘hold’, saying the company’s shares can jump more than 20%.

-- Peter Nurse contributed to this report