uh, 1 syscoin was 96 BTC at one point a short while back.
that's a little more warped than the usual exchange crap. someone somewhere has been screwing with things somehow.
I have seen this so many times on DEX just like forkdelta and etherdelta.
Someone just creating another joke order at the same time.
i don't know exactly how these decentralized exchanges you named work but in centralized ones like Binance the orderbook is a queue not a "choose whatever you want" line. which means if there are 3 sell orders like this (prices):
00.00004400
00.00040000
96.00000000
you first have to fill the first two orders on top before reaching the third one. and filling those two requires spending money. even if you execute an order on 96BTC price the system will automatically fill the first order and if there was anything left it will fill the next and next,.... it doesn't let you fill the last one.
now in reality there aren't just 2 orders there are A LOT and it will take A LOT of money to get there.