Vaccitech plc and Werewolf Therapeutics Inc. opened the last day of April with contrasting IPOs. Both priced mid-range, with Vaccitech raising $110.5 million, similar to Werewolf's $120 million haul. However, American depository shares of Vaccitech (NASDAQ:VACC), co-developer of Astrazeneca plc’s COVID-19 vaccine, fell 17.1% to $14.10 from a $17 open, while shares of cancer therapy developer Werewolf (NASDAQ:HOWL) boomed – until they didn't – climbing to $24 before closing about where they started, at $16.10.