In the past staff members have been allowed to sell up to 10%. But this whole “dilution” idea is a really pernicious misnomer. Dilution only matters if maintaining a particular percentage confers other rights, such as having a board seat, access to board meeting minutes, etc. That doesn’t apply to crowdfunding investors. @anon91821566 explained it well, and if you don’t believe that each subsequent round acts as a separate investment, then please refer to the spreadsheet in this post, which outlines very clearly that separate subsequent investments operate completely independently. Monzo are nice and allow you to maintain your (arbitrary) percentage if you choose to, but you need to evaluate each round on its own merits. “dilution” does not make you poorer in any way.