Parabilis Medicines set a new U.S. biotech IPO record after pricing a $770.5 million offering and debuting on Nasdaq. The company raised $670 million gross proceeds with an upsized share count and underwriters’ option exercise that added another $100.5 million, bringing total net proceeds to about $711.7 million. Shares jumped sharply after listing, rising 58% on the first full trading day to $31.60 before profit-taking and subsequent declines during the week. The report also noted Parabilis took the record from earlier 2026 IPO highs, including Kailera Therapeutics’ $625 million deal in April. Parabilis, based in Cambridge, Massachusetts, develops drugs and antibody-drug conjugates targeting historically “undruggable” proteins using stabilized helical peptides or Helicons, and it cited proprietary Helicon datasets collected over a decade of discovery as part of its valuation thesis.