On the 27th and 30th August 2013 Markus bought a lot of BTC, further faking the bull market (total net BTC bought by Markus = 297628). From the Willy report:
In this table, the first two trades (buy/sell pairs) are by some regular user with ID 238168. In the second trade, this user buys 0.398 BTC for $15.13. The next trade is some large market buy by Markus (ID 698630): note how the $15.13″ value from the previous trade seems to stick; regardless of the volume of BTC bought, the value paid is always $15.13. This is speculation, but perhaps for Markus, the Money spent field is in fact empty, and the program that generates the trading logs simply takes whatever value was already there before. In other words, Markus is somehow buying tons of BTC without spending a dime.
My reading of that analysis is that Markus/Wally had several "slave" accounts, used one after the other, that bought bitcoins continuously in small amounts from other users; with apparently valid trades, paying with non-existent USD, at 10% above market. Then periodically those slave accounts transferred the bitcoins to that master account; not by open trading, but by fake trades (not visible to the outside world), that had the same meaningless USD amount "15.13$" irrespective of the BTC amount or market price. The coins presumably were then withdrawn from the master account to some destination outside the MtGOX wallets.