The plan must specify amounts, prices and dates, or supply a formula, and the insider must not retain influence over execution. Amendments and terminations that look opportunistic undermine the defence.
Amendments to the rule added cooling-off periods between adoption and the first trade, longer for officers and directors than for others, a certification of no awareness of material-non-public-information, limits on overlapping plans, and disclosure of plan adoption and terms in quarterly filings. Sales under a plan are flagged on form-4.
For traders reading insider data, plan-flagged sales are largely noise, since they were scheduled months earlier. Non-plan open-market purchases remain the interesting subset.
Related: insider-trading, form-4, section-16-insider, material-non-public-information, short-swing-profit-rule