Understanding Perpetual Swaps: The Driving Force Behind Crypto's Trading Scene

Perpetual swaps, or 'perps', have emerged as the dominant force in the crypto market, with estimated annual trading volumes ranging from $40 trillion to $50 trillion. These financial instruments provide professional traders, hedge funds, and retail speculators with leveraged exposure to asset prices without requiring ownership of the underlying assets. However, the inner workings of perps remain poorly understood by many. To grasp the concept of perps, it's essential to examine their predecessors. In traditional finance, leveraged exposure to assets is typically achieved through futures contracts, which involve an agreement to buy or sell an asset at a predetermined price on a specific date. Upon expiration, the contract is settled, and traders must roll over their positions to maintain exposure. In the early days of crypto, this approach created persistent issues. 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 the automatic closure of positions, regardless of the traders' intentions. BitMEX, a derivatives exchange founded in 2014, attempted to address these problems by shortening contract durations, but this ultimately proved insufficient. The perpetual swap, developed by Ben Delo and launched on BitMEX in 2016, resolved these issues by eliminating the expiry date altogether. This created a derivative contract that tracks the price of an asset indefinitely, with no settlement date, rolling, or expiry. Traders can now hold positions for extended periods, ranging from hours to years. The absence of an expiry date, however, introduced a structural challenge: without a natural anchor, the contract price might deviate from the spot price of the underlying asset. To mitigate this, BitMEX implemented a mechanism that has since become the industry standard. Every eight hours, a payment is exchanged between traders on opposite sides of the market. If the perpetual swap price exceeds the spot price, indicating excess demand for long positions, long traders pay short traders. Conversely, if the perpetual swap price falls below the spot price, the payment is reversed. The exchange does not take a cut of this payment, known as the funding rate, which is calculated based on the deviation between the perpetual swap price and the spot price over the preceding eight-hour window. The further the deviation, the higher the funding rate. This creates a self-correcting equilibrium, where high funding rates discourage traders from holding positions, thereby pulling the price back toward the spot price. Market makers accelerate this process by shorting the perpetual swap and buying spot whenever a significant premium emerges, capturing the difference as profit. The funding rate mechanism is now widely adopted by major derivatives exchanges worldwide. Another defining feature of perpetual swaps is leverage. Most exchanges allow traders to control positions significantly larger than their deposited capital, with varying limits depending on the platform and jurisdiction. At its peak, BitMEX offered leverage of up to 100 times, meaning a 1% move in Bitcoin's price could result in a 100% gain or loss on a fully leveraged position. To manage the associated risks, perpetual swap platforms employ 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 this liquidation engine have become key competitive differentiators in the market. Perpetual swaps have become the primary venue for price discovery in crypto, with sharp moves in bitcoin typically originating in perp markets before spreading to spot. The structure developed by Delo in 2016 has proven durable enough that regulators in the U.S. 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 evolved into one of the most traded financial products globally.