Take a look at some of the biggest movers in the premarket.

Uber (UBER) — Uber shares rose 5.7% in the premarket after the ride sharing company revised its financial outlook higher for the third period. The company now expects to report between $22.8 billion and $23.2 billion in gross bookings for the third quarter, according to an SEC filing. It previously forecast $22 billion to $24 billion on its second-quarter earnings call.

Johnson & Johnson (JNJ) — Johnson & Johnson shares gained 0.8% in early morning trading after the pharmaceutical company said its Covid-19 booster shot is 94% effective when administered two months after the first dose in the U.S. The company said the booster increases antibody levels four to six times higher than just one shot

Apple (AAPL) — Shares of Apple ticked up 0.9% in the premarket after a Wall Street Journal report that the technology company is working on iPhone features to help identify depression and cognitive decline. The features would use sensor data to help detect these health issues, the Journal said, citing people familiar with the matter.

Chevron (CVX), Exxon Mobil (XOM) — Oil stocks rebounded in the premarket as crude prices rose. Chevron and Exxon Mobil each gained more than 1% in the premarket. The stocks were hit during Monday’s sell-off as concerns about global economic growth sent oil lower.

Enphase Energy (ENPH) — Enphase Energy shares rose 1.8% in early morning trading after KeyBanc initiated coverage of the stock with an overweight rating. The firm said the solar energy play had a solid base business and growing opportunities.

Vail Resorts (MTN) — Vail Resorts shares added 1.7% in the premarket after KeyBanc upgraded the stock to overweight from sector weight. KeyBanc said Vail Resorts should benefit from strong demand for winter vacations.

Big Lots (BIG) — Shares of Big Lots fell 1.3% in early morning trading after Piper Sandler downgraded the retailer to neutral from overweight. The firm said the end of fiscal stimulus will hurt Big Lots.