Anthropic is considering requiring employees to use preset Rule 10b5-1 plans if it goes public, while also debating first-day selling limits and post-IPO lockups, according to The Information via Reuters. Rule 10b5-1 plans are pre-set instructions that spell out when and how much stock gets sold, set up in advance to lower the risk that employee share sales draw scrutiny. Extending these plans to all employees would be unusual and could replace the more familiar trading windows many firms use after earnings. Anthropic is also weighing how much current holders can sell on day one and how long lockups should last, as these IPO mechanics control early share supply. For markets, if sales are routed through preset 10b5-1 plans, investors get a clearer map of potential insider and employee selling, which can reduce the “are they selling because they know something?” discount. Pairing that with first-day caps and longer lockups allows markets to start pricing the path of supply, while lockup expiration dates can become catalysts for volume spikes and short-term volatility.