Large holders of bitcoin are probably believers so I don't think they would do any detrimental action to the ecosystem on purpose. Plus, if they wanted to sell

Large holders of bitcoin are probably believers so I don't think they would do any detrimental action to the ecosystem on purpose. Plus, if they wanted to sell BTC they would not be so stupid to do it with a large market order (because it would act against their favour), OTC market exists (or even limit orders, which don't move the market but if anything, they make it more price-stable).