Haha, look at him marching his cash army up the chart. He's getting other people to buy up so he can sell again, methinks.
And now he's in full retreat to 2,50.
I believe the strategy is something like this. March a bunch cash out in the hope that other people put bids in front of your giant bids (because they'll feel more confident). When the bids build up enough, sell into the bids in front of your bids, then drop your giant bid and watch the market panic. Then buy back at a lower price. Repeat.
In effect, this "person" is providing liquidity. Rejoice!
Edit: But why would he drop it to $2.5 first? Also, the positioning of his two walls stands to make him lose a lot of money...