Understanding Perpetual Swaps: The Most Traded Financial Instrument in Crypto

Perpetual swaps, also known as perpetual futures or 'perps', have revolutionized the crypto market by providing traders with a unique instrument for leveraged exposure to asset prices without owning the underlying asset. With estimated annual trading volumes ranging from $40 trillion to $50 trillion, perps have surpassed spot trading in popularity among professional traders, hedge funds, and retail speculators. Despite their widespread adoption, the mechanics behind perps remain poorly understood. To grasp the concept of perps, it's essential to understand the traditional finance context in which they emerged. In conventional finance, traders typically gain leveraged exposure to an asset through futures contracts, which involve an agreement to buy or sell at a predetermined price on a specific date. Upon expiration, the contract settles, and traders must roll over their position to maintain exposure. However, this approach created persistent issues in the early days of crypto. Futures contracts traded at a premium to the spot price of bitcoin, causing confusion among retail traders seeking straightforward exposure. Moreover, contract expirations resulted in automatic position closures, regardless of the trader's intentions. In an effort to address these problems, BitMEX, a derivatives exchange founded in 2014, experimented with shorter contract durations, transitioning from quarterly to monthly, weekly, 48-hour, and eventually 24-hour expiries. Nevertheless, these adjustments proved insufficient. The perpetual swap, developed by Ben Delo and launched on BitMEX in 2016, eliminated the expiry date altogether, creating a derivative contract that tracks asset prices indefinitely. This innovation allowed traders to hold positions for extended periods without the need for rolling or settlement. The absence of an expiry date, however, introduced a structural challenge: without a natural anchor, the contract price could deviate significantly from the spot price. To address this issue, BitMEX introduced a funding rate mechanism, which has since become an industry standard. Every eight hours, a payment is exchanged between traders on opposite sides of the market, with the rate calculated based on the deviation between the perpetual swap price and the spot price over the preceding eight-hour window. This self-correcting mechanism helps maintain equilibrium by making it expensive for traders to hold positions with significant deviations from spot, thus pulling the price back toward spot. Market makers accelerate this process by shorting the perpetual swap and buying spot when a meaningful premium emerges, capturing the difference as profit. The other defining feature of perpetual swaps is leverage, which enables traders to control positions significantly larger than their deposited capital. To manage the associated risks, exchanges employ automated liquidation systems, which close positions before they can become negative, protecting the exchange from potential deficits. The speed and reliability of these liquidation engines have become a key competitive differentiator in the market. Perpetual swaps have evolved into the primary venue for price discovery in crypto, with bitcoin price movements often originating in perp markets before spreading to spot. The structure developed by Delo in 2016 has proven durable enough that regulators in the US are now exploring its application to traditional assets, with the CME potentially listing perpetual swaps on equities. What began as a solution to the limitations of crypto futures has become one of the most traded financial products globally.