Understanding Perpetual Swaps: The Hottest Crypto Trading Instrument

Perpetual swaps, also known as perps, are a dominant trading instrument in the crypto market, with an estimated annual volume of $40 trillion to $50 trillion. They surpass spot trading and are the go-to product for professional traders, hedge funds, and retail speculators seeking leveraged exposure to bitcoin and other assets without holding the underlying asset. However, the mechanics behind perps are not widely understood. To grasp perps, it's essential to understand their origins. In traditional finance, leveraged exposure to an asset typically comes through a futures contract, which expires on a specific date. When the contract expires, traders must roll their position into the next contract. In crypto's early days, this created issues, including futures trading at a premium to the spot price, known as basis, which confused retail traders. Every time a contract expired, positions closed, regardless of the trader's intentions. BitMEX, founded in 2014, attempted to solve this by shortening contract durations but ultimately developed the perpetual swap, which launched in 2016. The perpetual swap eliminates the expiry date, allowing traders to hold positions indefinitely. This created a structural challenge, as the contract price could deviate from the spot price without an expiry date to anchor it. BitMEX addressed this by introducing a funding rate mechanism, where traders on opposite sides of the market exchange payments every eight hours. If the perpetual swap price exceeds the spot price, long traders pay short traders, and vice versa. The funding rate is calculated based on the deviation between the perpetual swap price and the spot price over the preceding eight-hour window. This creates a self-correcting equilibrium, where high funding rates discourage traders from holding positions, pulling the price back toward the spot price. Market makers accelerate this process by shorting the perpetual swap and buying spot when a premium opens up, capturing the difference as profit. Leverage is another defining feature of perpetual swaps, with most exchanges offering high leverage limits. To manage the associated risk, exchanges use automated liquidation systems to close positions before they can go negative. Perpetual swaps have become the primary venue for price discovery in crypto, with regulators exploring their application to traditional assets. The structure developed in 2016 has proven durable, and perpetual swaps are now one of the most traded financial products globally.