Just take into account the value + size of the BTC portfolio. It's over 1m bitcoins now. If this was a conglomerate of some size and the value of the portfolio grew from $1m US to $1b US in such a short time, wouldn't there be a lot of pressure to sell and take a large amount of cash for each shareholder? I'd think there would be a LOT of talk about that and that, yes, it would be likely to see each person taking $10m US out at the very least. So, anecdotally, I see the fact/appearance that this hasn't happened as evidence that Satoshi's bitcoins are owned by one person. One person who owned so many BTC could sell enough to raise $10m without anyone really thinking much about it. But if a group of twelve, for example, owned that many bitcoins and each wanted to pull out $10m in cash, that size of a transaction goes noticed. Wasn't it just last week that someone did a $147m BTC transfer? It made headlines everywhere.