I angel invested two biotech start-ups in US. As biotech angels will be inevitabley subjected to huge dilution in the future. My way of anti-dilution is to be bound with founders' shares.
Two key terms in the founder agreement,
1. limited option pool, not bigger than the original issue shares
2. percentage lock with founders's shares. No matter how many round of dilution, my share percentage to founder's shares is fixed.
