The pool of company shares available for granting equity awards under a shareholder-approved stock plan registered with the SEC on Form S-8. Companies must monitor the share pool, and expected share use, to control dilution and run rate. This helps companies with their grant guidelines and lets them know when additional shares must be authorized for the share pool.

When a startup grows and has multiple funding rounds, managing and protecting its option pool become a focus, as explained in an article by a venture-capital professional at the website Techcrunch: A Founder’s Guide To Effectively Managing Your Options Pool.