There is no public market in your shares and no insider-trading window to pre-commit around, so Rule 10b5-1 is irrelevant on its face. What is portable is the thing the rule exists to produce: decide the rule before you have the information. The private-company equivalent is a shareholders’ agreement with a pre-agreed valuation formula and buy-sell terms, settled while everyone is relaxed, so that a departure, a dispute or a death does not get priced in the moment of maximum pressure. Boersma sold $106m without a single discretionary decision in November because he made the decision in February.