Rule 10b5-1 Trading Plans

A company's CEO wants to diversify some wealth out of company stock. That's completely reasonable — most of their net worth is tied up in one company. But as CEO, they are almost never "clean" of material non-public information: they know this quarter's numbers before the public does, they know about deals in progress, they know about problems before an earnings call reveals them. If they sell stock whenever they personally decide the timing looks good, every sale is a plausible insider trading claim waiting to happen, whether or not they actually used any inside information.

Rule 10b5-1 solves this by letting an insider set up a trading plan in advance, while they are not in possession of material non-public information, specifying exactly what will be bought or sold, in what quantities, and on what schedule (or triggered by a pre-set price). Once the plan is adopted, trades execute automatically according to its terms — the insider has no discretion over the timing of any individual trade anymore. Because the decisions were locked in before any inside information existed, a sale that happens to fall right before bad news becomes public isn't evidence of trading on that news — the insider genuinely couldn't have used information they didn't have yet when the plan was set.

The rule has been tightened over time after abuse: insiders were caught adopting plans, then cancelling and re-adopting them shortly before good or bad news, effectively using the "plan" as cover for opportunistic timing. Current rules require a cooling-off period (typically 90 days) between adopting a plan and the first trade under it, limit how often plans can be modified, and require certifications that the insider wasn't aware of material non-public information when the plan was adopted.