Understanding Perpetual Swaps: The Dominant Trading Instrument in Crypto

Perpetual swaps, also known as 'perps', are a dominant force in the crypto market, handling an estimated $40 to $50 trillion in volume annually. 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 directly owning them. Despite their widespread use, the mechanics behind perps are not well understood. To grasp perps, it's essential to consider their origins. In traditional finance, leveraged exposure to an asset typically involves a futures contract, which is an agreement to buy or sell at a set price on a specific date. When the date arrives, the contract expires and settles, requiring traders to roll their position into the next contract if they wish to maintain it. In the early days of crypto, this practice posed persistent problems. Futures traded at a premium to the spot price of bitcoin, a concept known as basis, which confused retail traders seeking straightforward exposure. Every time a contract expired, positions closed, regardless of the trader's intentions. BitMEX, founded by Arthur Hayes and Ben Delo in 2014, attempted to address this by shortening contract durations, moving from quarterly to monthly, weekly, 48-hour, and 24-hour expiries, but none of these solutions were sufficient. The perpetual swap, developed by Delo and launched by BitMEX in 2016, resolved the issue by eliminating the expiry date altogether, creating a derivative contract that tracks an asset's price indefinitely. There is no settlement date, no rolling, and no expiry, allowing traders to hold positions for hours or years. This created a structural challenge: without an expiry date to anchor the contract price, it would not naturally return to the spot price of the underlying asset. BitMEX solved this through a mechanism that has become the industry standard. Every eight hours, a payment is exchanged between traders on opposite sides of the market. If the perpetual swap trades above the spot price, indicating excess demand for long positions, long traders pay short traders. If the perpetual swap trades below spot, the payment is reversed. The exchange does not take a cut. The funding rate, which determines the payment rate, is calculated based on the deviation of the perpetual swap price from spot over the preceding eight hours. The further the deviation, the higher the rate. This creates a self-correcting equilibrium. When longs face a substantial funding rate, holding the position becomes expensive, reducing demand and pulling the price back toward spot. Market makers accelerate this process by shorting the perpetual swap and buying spot when a meaningful premium opens up, capturing the difference as profit. The funding rate mechanism is now used by every major derivatives exchange worldwide. Perpetual swaps are also defined by their use of leverage. Most exchanges allow traders to control positions significantly larger than their deposited capital, with limits varying by platform and jurisdiction. At its peak, BitMEX offered leverage of up to 100 times, meaning a 1% move in Bitcoin's price would result in a 100% gain or loss on a fully leveraged position. To manage the risk, perpetual swap platforms use automated liquidation systems. If a trader's losses approach the value of their deposited margin, the system closes the position before it can become negative, protecting the exchange from absorbing the deficit. The speed and reliability of the liquidation engine have been key competitive differentiators in the market and remain central to how exchanges compete today. Perpetual swaps have become the primary venue for price discovery in crypto, with bitcoin moves typically originating in perp markets before spreading to spot. The structure developed by Delo in 2016 has proven durable enough that U.S. regulators are now exploring its application to traditional assets, with the CME potentially listing perpetual swaps on equities. What began as a workaround for the limitations of crypto futures has become one of the most traded financial products globally.