The flash crashes happen. As long as you don't have a sell order on the market then it is just noise. Many people trade stocks with stop loss orders. The computer is told to sell if a stocks goes below a cretin point. You can take advantage of this buy putting in a very low bid on something , and if this happens again maybe you get filled. I don'[ know if cryptos have limit buy orders or stop losses. something to think about.
Or you can just pull the limit order and wait as $13 is where the price of ETH is "likely" going before the year is out anyway.
Yes, but someone needs to sell for you order to fill. Yes, its is a good idea the only loss is nothing if it does not fill. He up side is you get filled at a low price.
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.