UnitedHealth shares rose 3% in premarket trading on Wednesday after an 18% slump in the prior session.

UnitedHealth said its Chief Executive Andrew Witty resigned as of Tuesday, and the company suspended its annual forecast due to surging medical costs.

Chairman Stephen Hemsley, 72, who was CEO before stepping down in 2017, will assume the CEO title once again.

BigBear.ai Holdings shares jumped 6% in premarket trading on Wednesday after soaring 10% on Tuesday.

Hims & Hers Health shares rose 3% in premarket trading on Wednesday after soaring 16% on Tuesday.

Hims & Hers Health, a company specializing in telehealth and wellness, has entered into an agreement to issue $1 billion in convertible senior notes, according to a recent 8-K filing with the U.S. Securities and Exchange Commission. The notes, due in 2030, were sold in a private offering to qualified institutional buyers under Rule 144A of the Securities Act of 1933.

Aurora Innovation shares tumbled 17% in premarket trading on Wednesday.

Uber is offering $1 billion of senior notes exchangeable into shares of self-driving truck technology firm Aurora Innovation Inc.

The San Francisco-based ride-hailing company is marketing the notes to investors with zero coupon, according to people familiar with the matter. Uber is offering a conversion premium of 10% to 15% on the notes, the people said, asking not to be identified as the information isn’t public.

The notes are convertible into shares of Aurora, or into cash, or both, according to a statement earlier. Uber held about 23% of Aurora’s shares as of the end of December, data compiled by Bloomberg show.