He has billions of dollars worth of coins, you think he didn't sell any of them? He must have balls of steel pretty much. However there are times when there are coinbase transactions going back to 2010 which are being spent, maybe its Satoshi selling his mined coins in reverse of how they were mined.
Given that a single reward block of 50BTC is over $1M now, he can probably sell one block every 2-3 years and still live comfortably. Whats also suprising is that even if Satoshi stays silent, his friends or family or enemies might not. And someone by now would of slipped and his identify would of been revealed. However its still a mystery.
From what is known, he lived in London from 2004 to 2010. I myself lived in London from 2004 to 2013. I guess he was a computer science student just like me at that time. If satoshi is not one of my personalities then I might have met him somewhere around London in that time.