Thread by @patio11

Listening to a talk on frontrunning in decentralized exchanges running on blockchains and, holy cow, is everything about this wild.

slideslive.com/38911605/smart…

A decentralized exchange uses smart contracts to process orders.

So you broadcast your order to the entire Internet, in the clear, seconds before that order makes it into the order book, because blockchain.

Because blockchains are globally distributed timestamping services with low resolution, other interested parties on the Internet can retroactively insert/delete/etc their own orders after hearing about your order, before your order is officially timestamped / entered in book.

This works... about as well as you would expect.

It seems that in the main the problem is less "frontrunning" (though, good God) and more "When people fat-finger an order on one of the friendly web-accessible frontends for this, people can insert an order into the book to hit it before the cancel message takes effect."

And that feels like simultaneously a "Yep, putting in orders does run the risk of those orders being executed. Don't know what you wanted to happen." and "Oh, here we have testimony that someone is daytrading his village's combined savings pool."