At one time, the FBI held the distinction for single largest holding of bitcoin after the SilkRoad raid. But I think they've auctioned them off since then.
Wrong. At no point of time, the FBI was in the possession of more than
BTC200,000. On the other hand, Satoshi's Bitcoin holdings are estimated to be worth some
BTC980,000. So Satoshi has remained as the single largest holder of Bitcoin, ever since the mining started in 2009. Whether he has got the private keys to all of his coins is another question.