Rock Health’s latest market commentary reflects this tension clearly. In 2025, U.S. digital health startups raised $14.2B across 482 deals, a meaningful rebound from 2024, but the gains were uneven. Capital flowed to fewer companies, average deal sizes increased, and a small number of large rounds drove an outsized share of total funding. In other words, capital is still moving, but investor selectivity is sharper, and the burden of differentiation is higher. That makes “evidence” feel more important in diligence, even when different investors are using that word to mean very different things.

One investor may be asking whether your product is credible enough to take seriously. Another may be asking whether your business is de-risked enough to scale. A third may be asking whether your solution can work inside a real clinical or enterprise environment.

All three may say they want “evidence,” but they are not asking the same question.

The better question is not, “What evidence do investors want?”

It is, “What decision is this investor trying to make?”

That is what makes evidence useful.

There Is No Single Investor Definition of “Evidence”

In fundraising, “evidence” can mean several very different things.

Depending on the investor, it may mean:

• Feasibility: Can real users engage with the product as intended?
• Credibility: Is there enough scientific or clinical grounding to believe this is more than a compelling concept?
• Differentiation: Is there something defensible about the product, mechanism, or insight?
• Risk Reduction: Have you reduced enough uncertainty to justify the next check?

That is why two investors can ask for more evidence and still be reacting to entirely different gaps.

The word stays the same. The underlying diligence question does not.

For digital health founders, that distinction matters even more because evidence is rarely judged on a single dimension. In practice, companies are often evaluated across a mix of clinical credibility, claims, and real-world relevance, not just whether they have one study.

What Seed Investors Are Often Really Signaling

At Seed, investors are rarely asking for a fully de-risked business. They know that is not the stage.

What they are usually trying to determine is whether your company is a credible problem-solution bet worth learning alongside.

At Seed, “evidence” is usually less about polished outcomes and more about reducing the right early uncertainties.

They may really be asking:

• Can you clearly articulate the unmet need? 
• Have you shown that users, customers, or design partners actually engage? 
• Is there enough scientific, clinical, or behavioral rationale to believe the product is grounded in something real?
• Are you building evidence in a disciplined way, or just tracking activity?

This is where many founders overcorrect. 

They hear that investors want evidence and assume they need late-stage validation. But in many early-stage health and wellness companies, the stronger signal is not statistical significance. It is learning velocity.

A founder who can clearly explain what they tested, what they learned, what remains uncertain, and why the next validation step is the right one often sounds more investable than a founder with a dense slide full of premature outcomes.

At this stage, evidence is less about proving everything and more about showing disciplined learning.

Why The Meaning Shifts At Series A

By Series A, the bar changes.

The question is no longer just whether the product is plausible. It is whether the company is building toward scalability.

This is where evidence needs to do more than establish credibility. It needs to support confidence in scaling, adoption, and commercial readiness.

That may mean: 

• Stronger implementation consistency
• Clearer engagement patterns
• More buyer-relevant outcomes
• Better pilot-to-paid signals
• Data that ties directly to the commercial story

A dashboard full of usage metrics can still fall flat if it is not tied to a real investor concern. A study can still feel underwhelming if it does not map to how the company plans to grow.

If Seed-stage evidence says, “This is worth believing in,” Series A evidence increasingly needs to say, “This is worth scaling.”

Why Strategic Investors Often Mean Something Else Entirely

Strategic investors are often the biggest source of confusion because they may use the same language while evaluating something very different.

When a strategic investor asks for evidence, they are not always asking for stronger outcomes data. Often, they are trying to understand whether your company can function inside their ecosystem.

They may be asking:

• Can this fit into a real workflow?
• Will the intended users adopt it in context?
• Does it create value in a way that matters to our organization?
• Does it increase operational, clinical, or implementation burden?

In other words, they may care less about whether the evidence is academically impressive and more about whether it is operationally persuasive.

This is one reason founders sometimes walk away from strategic conversations believing they need a bigger study, when what the investor actually wanted was a stronger answer to a practical integration question.

That is especially true in digital health, where evidence often has to translate across investors, buyers, and clinical or operational stakeholders.

The Most Common Mistake: Chasing Outcomes Too Soon

This is one of the most expensive mistakes founders make.

A founder hears that investors want evidence and jumps straight to a large pilot, a formal outcomes study, or a validation effort before the product is stable enough to produce useful learning.

But early evidence should not be optimized for optics. It should be optimized for decision relevance.

When founders jump too quickly to outcomes, they often create one of two problems. Either the study is too early to produce a clean signal, which creates ambiguity instead of confidence, or the data looks impressive but does not answer the most important business question yet.

That is how teams end up with expensive evidence that still does not move diligence forward.

A stronger sequence is usually more disciplined: 

1. Establish that the product can be used as intended
2. Show that people engage with it meaningfully
3. Identify early signals that the mechanism is working
4. Then pursue stronger outcomes aligned with the next fundraising or commercial milestone

Not every company needs the same path. But almost every company benefits from getting the order right.

Why Evidence Without Interpretation Gets Discounted

Another common founder frustration is this:

“We have data. Why did they still say it was not enough?”

Because raw data is not the same thing as investable evidence.

Investors are not just evaluating what you measured. 

They are evaluating whether you understand:

• What it means
• Why it matters
• What decision it informed
• What still remains uncertain

This is where many founders lose credibility without realizing it. They present engagement data without context, pilot results without explaining the question the pilot was designed to answer, or outcomes without clarifying why those results matter commercially.

The issue is not always lack of evidence. Sometimes it is a lack of evidence interpretation.

That is often what separates a founder who sounds defensive from a founder who sounds fundable.

If you want to go deeper on this, we wrote about how to translate data into a more persuasive business story here.

The Better Question Founders Should Ask

If there is one shift that improves fundraising conversations, it is this:

Stop asking, “What evidence do investors want?”

Start asking, “What decision is this investor trying to make, and what evidence would help them make it with confidence?”

That question changes how you design studies, sequence validation, talk about traction, and present your story.

Instead of saying, “We ran a pilot and saw strong engagement,” a founder can say, “We ran this pilot to determine whether users would complete onboarding, return without human support, and use the core workflow consistently enough to justify a larger implementation test.”

That is not just a metric. That is a decision.

And in fundraising, decisions are what make evidence persuasive.

If this way of thinking resonates, our Science Strategy for Early-Stage Founders masterclass walks through how to choose stage-appropriate evidence, reduce uncertainty, and make clearer product, growth, and fundraising decisions.