Top Seed Investors in the US (2026): The Most Active Funds Writing First Checks

The US seed market is the most active in the world by deal count, but it is not one market. The right investor for an AI infrastructure startup in San Francisco is not the same as the right investor for a fintech company in New York or an enterprise SaaS tool in Chicago. Stage, geography, sector, and check size all vary significantly across US seed funds.

This is a guide to the most active seed investors in the United States in 2026, with notes on what each fund focuses on, typical check sizes, and what they are best known for backing.

Y Combinator

Y Combinator is the most active seed investor in the United States by deal count. In Q2 2026 alone, YC backed at least 225 seed, pre-seed, or convertible note rounds. The standard deal is $500,000 for 7% equity, with the option of additional funding through the YC continuity fund for top performers.

YC is sector-agnostic and runs two batches per year. The network and brand effects are significant: YC alumni include Airbnb, Stripe, Coinbase, and DoorDash. For founders accepted into the programme, the value extends well beyond the check.

Andreessen Horowitz (seed)

a16z runs a dedicated seed programme separate from its main funds. Seed checks typically range from $1M to $5M, and the firm has been particularly active in AI infrastructure, consumer applications, and enterprise software. a16z also runs a Scout programme that allows operators and founders in the network to make smaller investments on the firm's behalf, which means a16z presence at seed can come through multiple channels.

First Round Capital

First Round is one of the most established dedicated seed funds in the US. It focuses on the first institutional check into a company, typically $1M to $3M, and has backed Uber, Warby Parker, Square, and Notion at seed. First Round is known for its founder-focused approach and its portfolio network, which it invests in actively through events, resources, and introductions.

General Catalyst

General Catalyst operates across stages but has been one of the most active seed investors in recent years, placing third in deal count rankings in 2026 behind YC and a16z. It invests in AI, healthcare, and enterprise software with a particular interest in companies that have genuine structural advantages rather than pure execution bets. Based in San Francisco with a Boston presence, it has a wider geographic reach than most Bay Area-only funds.

Initialized Capital

Initialized was co-founded by Garry Tan and Alexis Ohanian and focuses on seed-stage investments in consumer products, developer tools, and SaaS. Check sizes run from $500K to $2M. The fund has backed Coinbase, Instacart, and Flexport at seed. It is one of the cleaner examples of a fund with a specific thesis rather than a broad mandate.

Lerer Hippeau

Lerer Hippeau is the dominant New York seed fund for consumer, media, and fintech companies. It focuses on New York-based founders and companies with $500K to $1M checks. Portfolio includes Allbirds, Giphy, and Warby Parker. For founders who want a New York-origin investor with a strong consumer network, Lerer Hippeau is the most active option in the city.

Boldstart Ventures

Boldstart is a New York-based fund that specialises in enterprise software, developer tools, and cybersecurity. It typically leads the seed round for technical founders building B2B products, writing checks from $500K to $1.5M. Portfolio companies include Snyk, BigID, and Superhuman. For enterprise founders who want a deep-expertise investor rather than a generalist, Boldstart is the most active seed-stage specialist in that category.

Uncork Capital

Uncork (formerly SoftTech VC) is a San Francisco-based fund focused exclusively on seed-stage B2B SaaS and developer tools. It has been writing first checks since 2004, making it one of the longest-running dedicated seed funds in the US. Check sizes run from $500K to $1.5M. The fund does not move upmarket: it stays at seed and follows into later rounds selectively.

Founder Collective

Founder Collective is structured differently from most seed funds: its limited partners are founders, and the fund explicitly avoids taking board seats or leading rounds, positioning itself as a supportive minority investor. Checks run from $500K to $2M across sectors. The fund has backed Uber, BuzzFeed, PillPack, and Coupang. For founders who want institutional capital without heavy investor involvement, it is a distinctive option.

Floodgate

Floodgate is a Palo Alto-based pre-seed and seed fund focused on what it calls "thunder lizard" companies: outliers with the potential to reshape a market rather than capture a slice of it. Check sizes run from $500K to $1.5M. The fund has backed Twitter, Lyft, Twitch, and Okta at the earliest stage. It is a fit for founders with a large market thesis and the ambition to match it.

Antler (US)

Antler operates differently from traditional seed funds. It invests at the pre-company stage, bringing together individuals to form startups rather than backing companies that already exist. In the US it operates primarily from New York, writing initial checks of $100K to $250K for equity, with follow-on investment available as companies develop. For founders who are still assembling their co-founder or validating their idea, Antler is the most accessible institutional entry point in the US.

SV Angel

SV Angel was co-founded by Ron Conway and has been one of the most prolific angel-to-seed investors in Silicon Valley for over a decade. It writes smaller checks ($250K to $1M) but brings a network that includes most of the Bay Area's major funds and operators. Portfolio includes Google, Facebook, Twitter, Airbnb, and Pinterest. SV Angel is less visible than larger funds but remains one of the most connected seed-stage investors in the ecosystem.

What to have ready before reaching out

US seed investors move faster than most. A warm introduction, a clear deck, and a ready data room are the minimum. The investor data room checklist covers what to prepare at seed stage, and Pitchwise lets you share documents with per-viewer tracking so you can see exactly when an investor reviews your materials.

Frequently asked questions

What is a typical seed round size in the US in 2026?

Median seed round sizes vary by sector. Across the market, seed rounds in 2026 typically range from $1M to $4M, with AI and deep tech companies often raising larger amounts at seed than SaaS or consumer companies. Pre-seed rounds, which precede a formal seed, typically range from $500K to $1.5M.

Do US seed investors fund international founders?

Most of the investors on this list will back international founders if the company is incorporated in the US (typically a Delaware C-corp) or is willing to reincorporate. YC, Antler, and Founder Collective in particular back founders from many countries. Incorporation in the US is usually more of a requirement than physical presence, especially for remote-first companies.

What is the difference between pre-seed and seed in the US?

Pre-seed is the round before a formal seed, typically used for initial validation: building an MVP, signing early customers, or completing a technical prototype. Investors at pre-seed are writing smaller checks ($250K to $1M) and making decisions with less data. Seed is the first round with meaningful institutional capital, usually after there is evidence of market demand. The line between the two has blurred in recent years, with many funds describing themselves as seed-stage while writing what would previously have been called pre-seed checks.