Wall Street Waits for the SpaceX IPO, These 2 Under-the-Radar IPOs Could Already Be Making You Money

SpaceX, the aerospace and AI company founded by Elon Musk, could be the largest IPO in history when it goes public later this year with a target valuation of $1.75 trillion. But if it hits that valuation, it would be valued at a whopping 95 times its 2025 revenue of $18.5 billion.

The bulls believe SpaceX could grow into that valuation as it expands its Starlink satellite constellation and launches more Falcon rockets. However, the bears believe the market's enthusiasm for SpaceX will quickly fizzle out as its valuations catch up to the stock. They'll also point out that it's unprofitable and faces stiff competition from smaller companies.

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Therefore, it might be smarter to wait for the hype to die down before hopping aboard that bandwagon. Instead of waiting for that to happen, investors should take a closer look at two under-the-radar growth stocks that went public last year: Heartflow (NASDAQ: HTFL) and Neptune Insurance (NYSE: NP). Let's see why they could already be making you money.

Heartflow

Heartflow, a developer of AI-assisted cardiac imaging services for non-invasive heart diagnostics, went public at $19 per share on Aug. 8, 2025. Today, it trades at about $29.

Cardiologists usually use catheters to determine if arterial blockages are restricting a patient's blood flow. With Heartflow's software, they can use AI to create a personalized 3D model of a patient's heart and arteries from a standard coronary CT scan without any invasive procedures. It also added additional tools for analyzing plaque levels for preventative risk assessments.

That disruptive approach attracted many institutional investors, even as some retail investors shunned the stock because it wasn't a "generative AI" company. Last year, several major insurance companies -- including UnitedHealth and Cigna -- expanded their coverage to cover Heartflow's new plaque analysis services. It's already being used in over 1,400 medical institutions, and that footprint will likely continue to expand.

In 2025, Heartflow's revenue rose 40% as its adjusted gross margin expanded 170 basis points to 77%. For 2026, it expects its revenue to rise 24%-26% as its adjusted gross margin expands to 80%-81%. It isn't a screaming bargain at nine times this year's sales -- and it will stay unprofitable for the foreseeable future -- but it could still have plenty of growth potential.

Neptune Insurance

Neptune Insurance, a provider of flood insurance policies, went public at $20 per share on Oct. 1, 2025. Today, its stock trades at about $28.

Unlike larger, more diversified insurance companies, Neptune focused solely on flood insurance because it's a massive, underserved market. For many decades, many flood insurance policies in the U.S. were tethered to FEMA's National Flood Insurance Program (NFIP), which has a slower underwriting process, outdated flood maps, and limited customization options.

To disrupt that aging platform, Neptune used a combination of machine learning, AI, and geospatial data to automate its underwriting and pricing services. In most cases, its proprietary "Triton" platform completed the entire process without any human underwriters. As a managing general agent (MGA), Neptune underwrites and administers policies -- but its third-party insurers and reinsurers bear most of the actual catastrophe risks. As climate change intensifies, more customers could flock to Neptune's platform to insure their flood-prone properties.

In 2025, Neptune's revenue rose 34%, its written premiums grew 34%, and its adjusted earnings before interest, taxes, depreciation, and amortization (EBITDA) rose 32%. For 2026, it expects revenue to rise 22% as its adjusted EBITDA margin improves by 50 to 150 basis points. It isn't cheap at 35 times this year's adjusted EBITDA, but it could be a great niche play on the evergreen insurance market -- which is generally well-insulated from recessions.

Leo Sun has no position in any of the stocks mentioned. The Motley Fool recommends UnitedHealth Group. The Motley Fool has a disclosure policy.