Nothing. No. They don't. Everyone gets diluted. VC firms and investors get diluted. There are ways to add anti-dilution clauses. It's complicated and I don't u

Nothing. No. They don't. Everyone gets diluted. VC firms and investors get diluted. There are ways to add anti-dilution clauses. It's complicated and I don't understand how they work. But AFAIK they are extremely rare and their presence will dissuade investors from investing. What prevents abuse? Trust. If you're a VC firm and you screw someone over, word will get around and all the good deals will dry up. If you're an entrepreneur and you screw someone over, word will get around and you'll never be able to raise money again (from the top firms, at least).