Given recent events, I think now might be a good time for someone to launch a dark pool perp DEX.
I have always been puzzled with the fact that everyone can see your orders in real-time on a DEX. The problem is worse on a perp DEX where there are liquidations.
Even with a CEX order book, where orders aren't linked to a specific individual, if you're looking to purchase $1 billion worth of a coin, you generally wouldn't want others to notice your order until it's completed. Otherwise, people might try to buy before you, effectively front-running you. In the case of a DEX, this can lead to MEV attacks. This results in increased slippage, worse prices, and higher costs for you.
For this reason, the large traders in TradFi use dark pools, which are often 10 times bigger than the “lit pools" (ie, normal orderbooks).
