Investing.com -- U.S. futures stagnated Wednesday, as investors awaited a speech by Fed Chair Jerome Powell which could offer clues over future monetary policy.

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

• Warner Bros Discovery (NASDAQ: WBD) stock fell 1.7% after the media giant narrowed its third-quarter loss, helped by the box-office success of “Barbie”, but still saw a 12% decline in advertising at its portfolio of TV networks.

• Bumble (NASDAQ: BMBL) stock fell 6.2% after the online dating company forecast fourth-quarter revenue below expectations in a sign that sticky inflation and growing competition were weighing on user spending on its apps.

• Robinhood (NASDAQ: HOOD) stock fell 9.2% after the online brokerage reported third-quarter revenue that fell short of estimates amid a decline in users.

• Upstart (NASDAQ: UPST) stock slumped over 27% after the AI lending platform disappointed with its quarterly results, while next quarter's revenue guidance fell short of expectations.

• Rivian (NASDAQ: RIVN) stock rose 8.8% after the EV manufacturer raised its production forecast for the full year by 2,000 vehicles to 54,000 units on the back of sustained demand for its trucks and SUVs.

  

• Upwork (NASDAQ: UPWK) stock surged over 22% after the freelancing platform beat expectations with its third-quarter earnings and revenues, while also offering strong guidance for the full year.

• Gilead Sciences (NASDAQ: GILD) stock fell 2% after the drugmaker said its third-quarter sales were little changed from a year earlier, but earnings rose mainly due to lower taxes.

• Lucid Group (NASDAQ: LCID) stock fell 5.1% after Cantor Fitzgerald downgraded the EV manufacturer to ‘neutral’ from ‘buy’ after the company reported its third-quarter results and cut its full-year production forecast.

• Take-Two (NASDAQ: TTWO) stock soared 9.5% on reports the eagerly-awaited new Grand Theft Auto game may be unveiled this week.

• Toast (NYSE: TOST) stock fell 17% after the restaurant software platform reported another quarterly loss and provided disappointing sales guidance for the upcoming quarter.