Jaan Tallinn’s early Anthropic stake becomes one of the IPO’s standout angel wins

What’s the story? Skype co-founder and AI-safety investor Jaan TallinnDealroom has a profile for this one. Try Dealroom → led Anthropic’s first priced round in May 2021 — a $124 million raise when most of the venture establishment passed. As Anthropic’s public S-1 and IPO path put a spotlight on early backers, Tallinn is widely cited among the clearest individual winners from that early check.

Context. Coverage of Anthropic’s cap table (including Newcomer) frames Tallinn as the Series A lead from the effective-altruism–adjacent angel network that funded the company before traditional VCs piled in. A September 2026 Wall Street Journal profile described him as sitting on one of Anthropic’s earliest stakes — a position that could pay him billions ahead of the listing. Tallinn has not publicly disclosed an exact ownership percentage; paper value will move with the IPO price and any lock-ups.

Related Dealroom coverage of Anthropic’s S-1 filing: Anthropic stuns markets with low burn and rumours of Oct "going vertical".

Sources: Newcomer · WSJ · Anthropic S-1 (SEC)