--- title: "US IPO Weekly Recap: Biotech, early-stage mining, and Bill Ackman close out the April IPO market" type: "News" locale: "en" url: "https://longbridge.com/en/news/284943270.md" description: "Four IPOs were priced last week, led by three biotechs: Hemab Therapeutics raised $302 million, Avalyn Pharma $300 million, and Seaport Therapeutics $255 million. Hemab's stock rose 89%, Avalyn's 66%, and Seaport's 10%. Silver Bow Mining raised $60 million but saw a 7% decline. Bill Ackman's Pershing Square raised $5 billion, with a 50% increase in stock price. Eleven SPACs raised $2.2 billion, marking the largest week for blank check issues since December 2021. The Renaissance IPO Index is up 6.5% year-to-date, outperforming the S&P 500." datetime: "2026-05-01T21:34:00.000Z" locales: - [zh-CN](https://longbridge.com/zh-CN/news/284943270.md) - [en](https://longbridge.com/en/news/284943270.md) - [zh-HK](https://longbridge.com/zh-HK/news/284943270.md) --- # US IPO Weekly Recap: Biotech, early-stage mining, and Bill Ackman close out the April IPO market Four IPOs priced this past week, led by three sizable biotechs. They were joined by 11 blank check listings. Coagulation disorder biotech **Hemab Therapeutics** (COAG) upsized and priced at the high end to raise $302 million at an $849 million market cap. Hemab is developing antibody-based therapies for inherited bleeding and coagulation disorders. Its lead candidate, sutacimig (HMB-001), finished Phase 2 and is ready for Phase 3 for Glanzmann thrombasthenia and Phase 2 for Factor VII deficiency. Hemab Therapeutics finished up 89%. Pulmonary fibrosis biotech **Avalyn Pharma** (AVLN) upsized and priced at the high end to raise $300 million at an $813 million market cap. Avalyn is developing inhaled antifibrotic therapies for rare respiratory diseases, with a focus on pulmonary fibrosis. Its most advanced candidates are AP01, which is currently in a global Phase 2b trial for progressive pulmonary fibrosis, and AP02, which is currently in a global Phase 2 trial for idiopathic pulmonary fibrosis. Topline data for both trials are expected in mid- to late-2027. Avalyn Pharma finished up 66%. Neuropsychiatric therapeutics biotech **Seaport Therapeutics** (SPTX) upsized and priced at the high end to raise $255 million at a $1.1 billion market cap. Its lead programs include GlyphAllo in Phase 2b for major depressive disorder and GlyphAgo in Phase 1 for generalized anxiety disorder, with additional preclinical candidates targeting depressive and related CNS disorders. Seaport Therapeutics finished up 10%. Exploration-stage mining company **Silver Bow Mining** (SBMT) upsized and priced at the downwardly-revised midpoint to raise $60 million at a $368 million market cap. The company owns approximately 3,347 acres in patented mineral claims in Silver Bow County, Montana, and is focused on silver, zinc, gold, lead, and copper. Silver Bow has yet to generate revenue. Silver Bow finished down 7%. While not included below, Bill Ackman’s investment management firm **Pershing Square Inc.** (PS) and affiliated closed-end fund **Pershing Square USA** (PSUS) completed their dual IPO, raising $5 billion. PS finished the week up 50% from its first opening trade. Eleven SPACs raised a combined $2.2 billion, the biggest week for new blank check issues by proceeds since December 2021. The deals were led by Michael Klein’s **Churchill Capital XII** (CXIIU), which raised $360 million in an upsized offering. **IPO Market Snapshot** The Renaissance IPO Indices are market cap weighted baskets of newly public companies. As of 4/30/2026, the Renaissance IPO Index was up 6.5% year-to-date, while the S&P 500 was up 5.7%. Renaissance Capital's IPO ETF (NYSE: IPO) tracks the index, and top ETF holdings include CoreWeave (CRWV) and Arm Holdings (ARM). The Renaissance International IPO Index was up 23.6% year-to-date, while the ACWX was up 9.1%. Renaissance Capital’s International IPO ETF (NYSE: IPOS) tracks the index, and top ETF holdings include Kioxia and Galderma. ### Related Stocks - [PSTH.ESC.US](https://longbridge.com/en/quote/PSTH.ESC.US.md) - [BIB.US](https://longbridge.com/en/quote/BIB.US.md) - [PSHZF.US](https://longbridge.com/en/quote/PSHZF.US.md) - [LABU.US](https://longbridge.com/en/quote/LABU.US.md) - [XBI.US](https://longbridge.com/en/quote/XBI.US.md) - [IDNA.US](https://longbridge.com/en/quote/IDNA.US.md) - [BBH.US](https://longbridge.com/en/quote/BBH.US.md) - [IBBQ.US](https://longbridge.com/en/quote/IBBQ.US.md) - [PBE.US](https://longbridge.com/en/quote/PBE.US.md) - [SBIO.US](https://longbridge.com/en/quote/SBIO.US.md) - [.SPX.US](https://longbridge.com/en/quote/.SPX.US.md) - [IPO.US](https://longbridge.com/en/quote/IPO.US.md) - [CRWV.US](https://longbridge.com/en/quote/CRWV.US.md) - [ARM.US](https://longbridge.com/en/quote/ARM.US.md) - [ACWX.US](https://longbridge.com/en/quote/ACWX.US.md) - [IPOS.US](https://longbridge.com/en/quote/IPOS.US.md) ## Related News & Research - [08:00 ETAvance Clinical Receives Frost & Sullivan's 2026 Global Company of the Year Recognition for Excellence in Biotech CRO Leadership](https://longbridge.com/en/news/286094661.md) - [Dyadic International Q1 net loss narrows](https://longbridge.com/en/news/286311192.md) - [Bill Ackman now has $13 billion in just 11 stocks](https://longbridge.com/en/news/286972743.md) - [Pershing Square launches $100M buyback after 16% share drop](https://longbridge.com/en/news/286640732.md) - [Rani Therapeutics Q1 contract revenue rises on Chugai collaboration; announces CFO transition](https://longbridge.com/en/news/286608288.md)