Are you suggesting that any given transaction is most likely to be a theft?

I think the point is that the only reason to transfer such a large sum of money is either buying/selling something or stealing. And considering there probably aren't many (if any) things one can buy with that many bitcoins, theft seems to be most likely scenario.

>I think the point is that the only reason to transfer such a large sum of money is either buying/selling something or stealing.

Perhaps you could be a little less specific?

>And considering there probably aren't many (if any) things one can buy with that many bitcoins, theft seems to be most likely scenario.

You could buy a lot of something from a private entity who really values Bitcoin.

Another option: Perhaps the security of the private key of the old address was in question, so a new address was created with a new, secure private key.

Could this not be some large purchase with a bitcoin payment attached to a contract?

Could a contract enforce a bitcoin transfer?

Or Cryptolocker/other cyber criminals