Form 4 code M reports the exercise or conversion of a derivative security, most often an employee stock option. It shows a change from derivative exposure into shares or another security form.
A code M exercise is not the same as an open-market purchase. The insider may be exercising previously granted options, sometimes followed by a tax withholding row or a market sale.
- Check the exercise price and transaction date when available.
- Look for paired code S or code F rows in the same Form 4.
- Compare post-transaction holdings to see whether shares were retained.
- Treat as derivative/compensation context rather than pure buying.