after looking at that bids over time chart i think maybe you are right some single entity that controls 50kbtc buy orders pulled them, moved them down, and are slowly moving them back up. already the bids from 70+ are up to 95k from 87k. yet the bid chart doesnt show any new money.
Who would be stupid enough to put new money to gox, while he could buy at >10% lower in other exchanges?