Bitcoin hoarding for charity: Buy some amount of bitcoin, and keep it in a series of of wallets dedicated to various causes. Precommit to hoarding all of the amounts for a significant time, but spend the ones with the most warm-fuzzy results the soonest because that results in pumping up the value of bitcoin.

Eventually, at a point where the value cannot be pumped further by expending more on warm-fuzzies, spend hoarded amounts on utilitarian-optimal causes in a way that leverages economies of scale to achieve maximum impact.