To stop vesting an option grant and return the unvested options back to the pool, head to the Cap Table tab, click on Plans and Equity Awards, click on the Cert number for the particular grant, then click the button "Stop Vesting" on the top. To see how we calculate vesting tranches, please see our Calculations article.
On the Stop Vesting.' Set the date from when you want the options to stop vesting. This will return the unvested options back to pool and leave the vested options with the grantee.
*To terminate an employee, see the article for how to record a lapse at the bottom.