Y Combinator is a startup accelerator that runs four batches of companies each year, each lasting three months. It invests $500,000 per company, structured as $125,000 for 7% on a post-money SAFE plus $375,000 on an uncapped SAFE with a most-favoured-nation clause. It backs companies at pre-seed and seed stage across sectors and geographies, with the programme and weekly meetups run from San Francisco.
Investment thesis
Y Combinator runs four three-month batches a year and invests USD 500,000 per company, structured as USD 125,000 for 7 percent on a post-money SAFE plus USD 375,000 on an uncapped SAFE with a most-favoured-nation clause. It backs pre-seed and seed companies across all sectors and geographies from its programme in San Francisco.
Y Combinator invests at Series A. Sesamers tracks 4 portfolio companies across 4 rounds, 1 of them as lead investor. Its most recent tracked deal: HyLight, Oct 2026.
Portfolio
Past investments
| Company | Round | Role | Date | Round size |
|---|---|---|---|---|
| HyLight Bretigny-sur-Orge, France Read the announcement → | Series A | Participant | Oct 2026 | €13M |
| Sensible Biotechnologies Oxford, United Kingdom Read the announcement → | Series A | Participant | Oct 2026 | €41.9M |
| Spott Leuven, Belgium Read the announcement → | Series A | Participant | Sep 2026 | €18.3M |
| Pretzel AI San Francisco, United States | Pre-seed | Lead | Apr 2024 | €450K |