Basis Decay
Basis decay refers to the gradual convergence of the price of a futures contract toward the spot price of the underlying asset as the contract approaches its expiration date. In cryptocurrency markets, this phenomenon is often observed in perpetual futures where funding rates act as the mechanism to keep the contract price tethered to the spot index.
When the basis is positive, the futures price trades at a premium to the spot, and as time passes or funding payments are made, this premium erodes. Traders often capture this decay through cash-and-carry arbitrage strategies, where they go long on spot assets and short the futures contract.
As the basis decays, the convergence provides a predictable return for the hedged position. This process is essential for market efficiency, ensuring that derivative pricing does not deviate indefinitely from the physical asset value.
It effectively represents the cost of carrying the position or the market sentiment regarding future price direction.