04:07 AM EDT, 10/11/2024 (MT Newswires) -- Upstream Bio (UPB) said Thursday it priced its initial public offering of 15 million common shares at $17 apiece for expected gross proceeds of $255 million, up from the initial size of $200 million.

Underwriters have been granted a 30-day option to purchase up to about 2.3 million additional shares.

The offering is set to close on Oct. 15.

Shares of the biotechnology company are expected to begin trading on the Nasdaq Global Market this Friday under the ticker symbol, "UPB."