Solo Founders Are 36% of New Carta Startups. AI Changed the Count, Not the Odds

About 36% of startups founded on Carta in 2025 had a single founder. Those same solo founders closed just 20% of the funding rounds recorded on the platform that year. Solo founder startups are no longer unusual, and the tools that made them easier to start have not made them easier to fund. AI changed how many one-person companies exist. It barely moved the odds that a venture investor writes one a cheque.

Is solo founding rising, and does it get funded? Yes, it is rising. Carta data puts solo founders at about 36% of new startups in 2025, up from under a quarter in 2019. Funding has not kept pace. Solo-founded companies closed 20% of rounds in 2025, so a solo founder raises at roughly half the rate their share of new companies would predict.

What Carta's solo founder data actually shows

Carta runs cap tables and equity administration for tens of thousands of US startups. When a company incorporates through Carta or moves its cap table there, Carta can see how many founders hold common stock at the start. That makes it the largest regular source of founder-count data in US venture.

It is also a platform, not a census. The companies on Carta are disproportionately the ones that intend to raise venture money or issue equity. Every figure in this post describes that population, not small business in general.

The climb from 2019 to 2025

Carta's Solo Founders Report, published in December 2025 with the advocacy group Solo Founders, gives the cleanest single series. The share of new startups with one founder rose from 23.7% in 2019 to 36.3% in the first half of 2025. That is a 12.6 point rise in roughly six years.

An earlier Carta analysis by Peter Walker, who leads the company's insights team, put the decade-long move at 17% to 30%. He noted the climb steepened after ChatGPT launched in late 2022. Timing is not cause, a point that returns in the limitations section.

Carta has published three different figures for 2024, and you should know that before quoting any of them. The table below sets them side by side.

Carta does not explain the restatement of 2024 from 35% to 31% in any page reviewed for this post. A change in denominator or cohort definition is the likely cause, but that is inference. Use one report's series at a time and never mix years across them.

My view is that the disagreement matters less than it first appears. Every version shows solo founders rising, and every version shows them under-funded relative to their share. The direction is stable even though the decimal points are not.

Solo founder startup statistics at the funding stage

The more useful number is the ratio between a group's share of new companies and its share of funding. Call it the funding rate. A group that is 30% of new startups and closes 30% of rounds has a funding rate of 1.0, which is parity.

Run the three Carta comparisons through that lens and they converge. Solo founders sit at about 0.49 on priced-round cash in 2024, about 0.49 on VC-backed companies in 2024, and about 0.56 on rounds closed in 2025. Those ratios are this post's arithmetic on Carta's published figures, not numbers Carta published itself.

Two-founder teams sit at parity

The comparison group explains the gap. In 2025, two-founder teams were about 36% of new startups and closed 36% of rounds. They were tied with solo founders as the most common team shape and funded exactly in proportion to their numbers.

So the market is not penalising small teams in general. It is penalising the absence of a second founder. That distinction should shape what a solo founder does about it, and it is why I would not read the gap as simple investor prejudice.

Carta says the share of venture dollars going to solo founders is growing. The move from about 0.49 to about 0.56 fits that claim. But the 2025 figure counts rounds while the 2024 figures count dollars and funded companies, so part of the apparent improvement may be a change of yardstick rather than a change in behaviour.

Rounds are the friendlier measure for solo founders because small rounds count the same as large ones. If solo founders mostly raise smaller cheques, a count of rounds flatters them and a count of dollars does not.

What AI changed for one-person startups

The clearest AI signal in Carta's data is not founder count. It is how few people a funded startup now employs.

Seed and Series A teams shrank by about half and a third

Carta reported in 2026 that the median seed-stage startup on its platform employs about 5 people, down from roughly 10 in 2021. At Series A the median fell from 26 to 17. Its H2 2025 compensation report put the median seed team even lower, at 4.

Carta has been careful about cause. Its own layoffs analysis said AI had not clearly pushed layoffs up, though it may be playing a role at the margins. A tighter funding market after 2022 also forced smaller teams, AI or not.

Solo founders hire sooner, not later

The counterintuitive finding sits in the hiring data. Solo founders take a median 399 days to make their first hire, against 480 for multi-founder companies.

If AI were replacing the team outright, you would expect solo founders to wait longer. They do the reverse. The simplest reading is that a solo founder's first employee does the job a co-founder would otherwise have done. AI compresses the team that comes after that, not the need for a second pair of hands.

Carta also notes that time to first hire rose for both groups. That is the pattern you would expect if AI tools let every founder go further before hiring, and it is equally what a cautious funding market produces. The data cannot separate the two.

Revenue per employee is the other half of this story. How the smallest AI-native teams compare on that measure is covered in the analysis of AI-native revenue per employee, which is where the lean-team thesis is strongest.

What AI did not change: the venture filter

The table below is the short version of the argument. Read the right column as the part a solo founder cannot automate.

Investors are pricing key-person risk, not productivity

A venture investor at seed is buying a probability of a large outcome. A solo founder concentrates that probability in one person's health, judgement and stamina. AI raises what that person can output. It does nothing to the risk that the one person leaves, burns out or turns out to be wrong.

That is why I expect the funding gap to narrow slowly rather than close. A productivity tool answers the objection investors used to raise, which was "one person cannot build this". It does not answer the objection they are actually pricing, which is "one person is a single point of failure".

The same logic explains why the funded solo company often looks like a two-founder company with a different cap table. The first hire carries real equity and real authority. Carta's ownership data, examined in the breakdown of how AI cap table terms are shifting, is the place to check what that hire costs.

Seed to Series A: the gate solo founders still face

Raising a seed round is the first filter. The harder one sits between seed and Series A, and nothing in Carta's data suggests it has loosened for anyone.

Graduation rates are low for every founder

Carta reported that only about 17% of companies that raised seed in 2022 reached Series A within two years, against roughly 25% to 30% for the 2018 cohort. A Carta benchmark from March 2026 treats 15% after two years as low, 25% as medium and 35% as high.

Timing has eased a little. The median gap between seed and Series A was 1.9 years for rounds closed in Q4 2025, down from a peak of 616 days in Q2 2025 per Carta. Those are figures for all founders. Carta has not published a solo-only graduation rate in any report reviewed here.

That missing number is the one this post set out to find, and it does not exist publicly. The honest answer to "what happens to solo founders at Series A" is that the public data stops at seed. The best available proxy is the funding rate above, which shows the filter working at roughly half strength from the first priced round.

Across all founding teams, Carta's 2026 ownership report found the median founding team keeps about 56% of fully diluted equity at seed and 36% at Series A. A solo founder starts with all of the founder equity, so the same dilution leaves them with a larger personal stake.

That is the real economic case for solo founding, and it is a strong one. It is also the reason investors scrutinise the structure harder. A founder holding 36% alone at Series A has fewer people with skin in the game beside them.

For a solo company that never intends to raise, none of this applies, and the economics look very different. The economics of one-person micro-SaaS covers that path, which is a separate business from a venture-backed solo startup.

Where this argument is weakest

Three objections deserve a straight answer, and one of them could reverse the conclusion.

Carta is not the startup economy

Carta sees companies that chose Carta. If cheaper incorporation products drew more solo founders onto the platform after 2022, the rise in solo share could partly be a change in who uses Carta rather than a change in how startups form. Nothing reviewed here rules that out, and Carta has not published a cohort-mix adjustment.

The funding gap is less exposed to this problem. A selection effect that adds more early, unfunded solo founders would depress their funding rate. That is a genuine reason the gap might be overstated, and a reader should hold the 0.49 figure loosely for that reason.

The headline report was co-produced with an advocate

The Solo Founders Report 2025 was published by Carta together with Solo Founders, an organisation that exists to promote solo founding. The underlying cap-table data is Carta's, but the framing around AI and productivity carries a point of view. Treat the interpretation as the authors' argument and the numbers as Carta's.

AI is a timing correlation, not a measured cause

No Carta report measures AI tool usage by founders. The link between AI and solo founding rests on timing: the climb steepened after late 2022. Higher interest rates, smaller seed rounds and remote hiring all moved in the same window. The strongest version of my argument is "AI made solo founding more common and did not fix the funding gap", and the first half of that sentence is inference.

What a solo founder should do with this data

If you are a solo founder planning to raise, the data says your problem is not output. It is the single point of failure. Your pitch should address that risk directly rather than show how much you shipped alone.

I would also stress-test the product against platform risk before the pitch. A solo company built mostly on a model provider's API is exposed in ways a larger team can absorb and one person cannot. The kill-zone test for AI startups is the quickest way to check whether your category is one a foundation model vendor is about to occupy.

And be honest about what your code costs to maintain. Fast solo shipping with AI tools often leaves a cleanup bill that arrives exactly when the first hire joins, which is the subject of the analysis of the vibe coding cleanup bill.

Frequently asked questions

Where to start

If you are a solo founder raising in the next six months, write down the answer to one question before any pitch meeting: who runs this company if you cannot for 30 days? Name the person, list what they can access, and state what equity they hold. That paragraph addresses the risk investors are actually pricing.

If you invest in or advise early companies, ask Carta or your own portfolio data for the one number missing from the public record, which is the seed to Series A graduation rate split by founder count. Until someone publishes it, every claim about solo founders at Series A, including the ones in this post, is a proxy.

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