Cartoon guide to Perps

This post explains perpetual swaps ("perps") through four equivalent mental models, arguing they are mathematically identical. It says a perp is natively tied to one exchange, with its mark price, based on exchange trading, tracked against an index price from an external exchange, and that a funding fee paid between longs and shorts pushes the two together. Using an example where bitcoin jumps from $100k to $110k, the author shows a perp can be modeled as a PNL loan, as a loan swap, and as a series of rolling one-day futures, with Sam Bankman-Fried cited as showing the one-day-future scheme. The post also notes that margin and liquidations, backed by an insurance fund, keep the system safe only if liquidations happen quickly and the fund is adequately capitalized.