Neptune Insurance Holdings Sets Terms for $350 Million IPO

Neptune Insurance Holdings, a U.S.-based underwriter and distributor specializing in E&S flood insurance, announced the terms of its IPO on Monday.

Headquartered in St. Petersburg, Florida, Neptune plans to raise $350 million by offering 18.4 million shares (all secondary) at a price range of $18 to $20 per share. Cornerstone investors T. Rowe Price and AllianceBernstein have expressed interest in purchasing up to $75 million of the offering, representing 21% of the deal. At the midpoint of the price range, the company would achieve a fully diluted market capitalization of approximately $2.8 billion.

Founded in 2017, Neptune operates as a data-driven managing general agent (MGA), helping homeowners and businesses manage flood risk. Its product portfolio includes primary and excess flood insurance as well as parametric earthquake insurance, all distributed via a national network of insurance agencies. Neptune does not assume insurance risk or handle claims; instead, it underwrites and manages policies on behalf of insurers and reinsurers using its proprietary platforms Triton for underwriting and Poseidon for policy administration.

For the 12 months ending June 30, 2025, Neptune reported revenue of $137 million. The company plans to list on the New York Stock Exchange under the ticker symbol NP.

Morgan Stanley, J.P. Morgan, BofA Securities, BMO Capital Markets, Goldman Sachs, Evercore ISI, Deutsche Bank, Keefe Bruyette & Woods, Mizuho Securities, Piper Sandler, Raymond James, and TD Securities are acting as joint bookrunners for the offering, which is expected to price during the week of September 29, 2025.