MtGox pumping and wash trading with Willy bot. Bitmex trading against and liquidating customers. Coinbase hiring Litecoin creator Charlie Lee and having him frequently wash trading 99% of LTC volume. Each of these has been _the_ preeminent exchange at some point in time, just as OpenSea is for NFT.
FTX was born from one of if not the largest crypto trader/market maker, and one of two known Tether customers (who apparently account for a large majority of Tethers). Alameda was the only/largest liquidity provider on FTX for some time. Binance has been similarly accused (without solid proof) of trading against customers. Of course they claim to have walls between these relationships. But then again, so did Mt Gox, Bitmex, Coinbase, OpenSea and loads of others that would take too long to mention.
Crypto is a casino where there are a handful of dealers that are running thousands of tables. They are all colluding. The grift is to exchange real fiat currency for chips at their casino.
It has been proven at a shocking number of blue chip institutions (dare I say a majority). Given our expected likelihood of uncovering these things, it seems highly probable that it’s happening everywhere.