He never moved a single coin. Not entirely true, he did some test transfer to Hal Finney, but that's it. He/they may be dead, or he/they may be planning to dump his/their stash at once. If not, why Satoshi did not sell coins till now? Why Satoshi did not buy anything with bitcoins? Is all in the blockchain. His coins never moved apart from some well documented transactions to early cooperators.
Maybe he accidentally formatted his hard-drive
