It was fake money buying real BTC. Most logical explanation.
I've heard that before. Can you explain where the BTC are if the bot actually purchased them with fake money? I've never seen any explanation proving that Gox ever had those actual BTC.
As I understand it, the theory is that mtgox lost a
lot of coins to one or several hacks way back, and kept it quiet. They then proceeded to "buy" BTC with fake usd on their platform, hoping to leverage that into sufficient arbitrage profits to recoup the coins they had lost.