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.
| 15 IPOs During the Week of April 27th, 2026 | |||||
|---|---|---|---|---|---|
| Issuer Business | Deal Size | Market Cap at IPO | Price vs. Midpoint | First Day Return | Return at 05/01 |
| Hemab Therapeutics (COAG) | $302M | $849M | 6% | +89% | +89% |
| Phase 3-ready biotech developing blood coagulation disorder treatments. | |||||
| Avalyn Pharma (AVLN) | $300M | $813M | 6% | +64% | +66% |
| Phase 2 biotech developing inhaled medicines for rare respiratory diseases. | |||||
| Seaport Therapeutics (SPTX) | $255M | $1,079M | 6% | +10% | +10% |
| Phase 2 biotech developing therapies for neuropsychiatric indications. | |||||
| Churchill Capital XII (CXIIU) | $360M | $484M | 0% | +1% | +1% |
| Blank check company founded by dealmaker and former Citi executive Michael Klein. | |||||
| General Catalyst Merger (GCGRU) | $350M | $402M | 0% | +1% | +1% |
| Blank check company backed by General Catalyst targeting aerospace and defense. | |||||
| Mountain Crest Acq. 6 (MCAHU) | $60M | $87M | 0% | +0% | +0% |
| Sixth blank check company formed by Suying Liu targeting businesses in North America and Asia Pacific. | |||||
| Irenic Acquisition (IACQU) | $220M | $281M | 0% | +0% | +0% |
| Blank check company formed by Irenic Capital Management targeting aerospace and defense. | |||||
| CH4 Natural Solutions (MTNE.U) | $200M | $269M | 0% | +0% | +0% |
| Blank check company backed by Impact Ag, Riverstone's David Leuschen, and Overview Capital's Lauren Singer. | |||||
| Quantum Leap Acquisition (QLEPU) | $200M | $269M | 0% | n/a | +0% |
| Blank check company targeting AI, quantum computing, and blockchain technology. | |||||
| Plutonian Acquisition II (PLUNU) | $100M | $131M | 0% | n/a | +0% |
| Blank check company targeting energy storage, telecom, and consumer sectors. | |||||
| West Enclave Merger (WENC.U) | $100M | $140M | 0% | +0% | +0% |
| Blank check company targeting Mexico and Latin America-focused businesses. | |||||
| Forefront Tech Acq. (FTHAU) | $100M | $137M | 0% | +0% | +0% |
| Blank check company targeting blockchain-enabled AI, digital trade identities, and robotics. | |||||
| RRE Ventures Acquisition (RREVU) | $250M | $333M | 0% | +0% | +0% |
| Blank check company affiliated with RRE Ventures targeting transformative sectors. | |||||
| Collective Acquisition II (CAIIU) | $220M | $295M | 0% | -1% | +0% |
| Blank check company targeting finance, defense technology, and AI. | |||||
| Silver Bow Mining (SBMT) | $60M | $368M | -15% | -7% | -7% |
| Exploration-stage mining company with projects in Montana. | |||||
| 4 Filings During the Week of April 27th, 2026 | |||
|---|---|---|---|
| Issuer Business | Deal Size | Sector | Lead Underwriter |
| First Breach (FBDT) | $0M | Industrials | |
| Ammunition manufacturer for commercial, law enforcement, and military markets. | |||
| Aussie Aussie Acquisition (AAAU.RC) | $100M | SPAC | Kingswood |
| Blank check company targeting defensible market positions. | |||
| GSR V Acquisition (GSRVU) | $200M | SPAC | Polaris |
| Blank check company led by SPAC veterans targeting companies with leading market positions. | |||
| Berto Acquisition II (GUACU) | $250M | SPAC | Needham |
| Blank check company targeting AI and AI infrastructure, backed by SPAC veteran Harry You. | |||
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.
