How the hedge is supposed to earn
When funding is positive, traders long the perpetual pay traders short it. Hold $1,000 of spot and a $1,000 short perpetual, and a price move gains on one leg about what it loses on the other, while the short collects funding.
Each payment is position value × funding rate, and only positions open at the settlement time pay or receive it. Rates and intervals can change, and if the rate turns negative, the short pays instead.