The strategy "might" work when trading shares on the U.S. equity exchanges but I doubt that transaction that happend with ETH is anything but a single trade made between two computers. It may have been "staged"....they do it all the time trading stocks. The thing to note is simply that computerized trading algos in fact executed that buy/sell order. If they can do it once...they can do it again. I doubt you will see a 50%+ gapup in ETH price like that show up on a chart. Buyer "beware" as far as ETH goes.