On the first day of the Anthropic IPO, up to 316 million Class A shares can be sold.

Anthropic’s second amended SEC filing discloses that up to 316 million Class A common shares could be eligible for sale on the first trading day after its IPO, representing about 38.3% of the 825 million-share offering. The offering is expected to be priced at $70–78 per share, with 801.35 million newly issued shares and 23.65 million shares sold by existing holders. The filing also details lock-up exceptions covering roughly 15.5 billion Class A shares, including convertible amounts, which could affect early trading liquidity. The split between new issuance and existing-share sales, alongside the unusually large first-day eligible float, is the key focus for investors assessing post-listing supply. Next, watch final pricing, the exact first-day sellable share count, and whether lock-up terms change in subsequent filings.