Almost no single entity has that much BTC (as of 2016 only ~15 million Bitcoins exist), to acquire it someone would have to aggregate the Bitcoins from many other entities by via buys on a Bitcoin exchange. This would cause a massive spike in the price of Bitcoin.

Interesting to note: there has been no new Bitcoin block for the last 1 hour 23 minutes. This happens from time to time, but it is a little suspicious.

See https://blockchain.info/