I had no idea that they were sitting on such a large stash of bitcoins (from the article, 250K). This leads me to believe that they have been trading on their own exchange to keep the USD / BTC price depressed.

For example, if the "market" decided that there was a 50% chance Mt. Gox was never going to solve their banking problems and allow unlimited fiat withdrawals, then you would expect there to be a 100% price premium for BTC on Mt. Gox. However, that would send a VERY scary message in terms of their viability, which would quickly become a self fulfilling prophecy, so Gox could sell some of their stash to keep the price premium to say, 10%. If they tried to push it all the way down to a 0% premium, though, they would quickly run through all their BTC.

Since the price premium has been stable at almost exactly 10% for months, that suggests SOMEONE is manipulating it, probably to keep it low. Does anyone care to look in the blockchain and do the deobfuscation to see if my theory is correct?