Your cap table has two key share counts: basic shares outstanding and fully diluted shares.

Basic shares outstanding include only issued common and preferred shares currently held by shareholders. Fully diluted shares include those plus all potential future shares from option pools, warrants, SAFEs, convertible notes, and other convertible instruments.

Investors value companies on a fully diluted basis because it reflects total potential ownership.

For example, if a startup has 8M basic shares outstanding, a 2M option pool, and raises a Series A issuing 2.5M shares, the investor owns 23.8% on a basic share basis (2.5M / 10.5M), but only 20% on a fully diluted basis (2.5M / 12.5M).

As option pools expand and more convertible instruments are added, the gap between basic and fully diluted ownership widens. This is why ownership is negotiated and modeled on a fully diluted basis.

Anthropic recently named eight firms as unauthorized to provide access to buying or selling its shares: Open Doors Partners, Unicorns Exchange, Pachamama Capital, Lionheart Ventures, Hiive (for new offerings), Forge Global (for new offerings), Sydecar, and Upmarket.

What happened: As Anthropic approaches a potential IPO, demand for its shares in private markets has surged. However, direct transfers of pre-IPO shares are often complex. As a result, investors rely on Special Purpose Vehicles (SPVs) to gain exposure to the company.

In some cases, these SPVs do not directly hold Anthropic shares but instead invest in other SPVs that claim to hold the shares, creating layered and indirect ownership structures.

Beyond SPVs, Anthropic has also taken aim at derivative instruments, tokenized products, and other structured securities marketed as Anthropic investments, even though investors receive only economic exposure rather than a direct ownership stake.

Why this matters: This is a reminder that transfer restrictions and Right of First Refusal (ROFR) provisions are not just legal boilerplate. They allow private companies to control who can acquire interests in their shares, prevent unauthorized secondary trading, and block structures that create economic exposure without the company's approval.

Sources: TechCrunch | Axios | Aurum