Actually the sell wall might not be bought. As the price came close, the seller just cancel its sell order, and therefore, you could not find this sell order, and it looks like the sell wall is bought. Now the seller set up another sell wall at another higher price so you find it they are back again. The good news of finding such big sell wall is that it indicates that the whales are collecting XRP at their bounded low price (through the sell wall effect), and once they collect enough qty, they will start to pump the price up. So now the best strategy is to collect XRP same as the whales so you could join the pump and dump games with the whales later on. Otherwise, you could just only look at the price and say whaaaaaaaaaaaaaaaaa....