Their sheer size also represents two reasons against their investing significantly in bitcoin: one, any buying or selling on their part will significantly move

Their sheer size also represents two reasons against their investing significantly in bitcoin: one, any buying or selling on their part will significantly move the price of BTC because the markets are so thin, and two, there are regulations that force them to control risks, and I'm not sure what, if anything, such regulations have to say about buying cryptocurrencies.