This is a fantastic read.

In one Aug. 10 (2020) transaction on the Ethereum blockchain, a trader appears to have used a series of transactions in tether and USDC on the decentralized cryptocurrency exchanges Uniswap, Curve and dYdX to net a tidy $40,000 profit off a $45,000 initial investment. That works out to an 89% gain in what was likely a matter of minutes.

1) Trader started with roughly $45,000 in USDC tokens and borrowed another $405,000 on dYdX, for a total of $450,000 in USDC.
2) Exploiting temporary differences between the stablecoins’ face value of $1 and quoted prices, the trader was able to use Uniswap to exchange the $450,000 of USDC for $492,000 of USDT.
3) Trader swapped $492,000 of USDT for $492,000 of USDC on Curve.
4) Trader paid off the $405,000 loan from dYdX and had $87,000 USDC remaining.
5) The transactions cost about $2,000 in fees.
6) Trader netted $40,000 profit on $45,000 of initial capital.