[sokoloff]

10b5-1 plans do not have to be filed with the SEC.

(The use of a 10b5-1 is also not technically a legal requirement, but is a workaround to allow planned sales even if you become aware of material, non-public information between the time of entering into the plan and the time of the trade.)

[hinkley]

You can prove the boss had an intention to sell his stock based on a feeling of future doom (or just greed). What’s tougher to prove is whether he delayed an announcement by a week so one more sale went through before the stock took a hit.

Or speeding up good news so his scheduled sale rides the high.

[throwaway2048]

the best thing about them is you can constantly schedule large stock sales, and just cancel the ones that don't favour you.

Look ma, no inside information.