Spread Convergence
Spread convergence is the process where the price difference between two related assets or the same asset on different markets narrows over time toward its theoretical equilibrium. In arbitrage, traders bet that this gap will close, allowing them to profit from the normalization of prices.
This movement is driven by market participants buying the undervalued asset and selling the overvalued one, which creates buying pressure on the former and selling pressure on the latter. The speed of convergence depends on market efficiency, transaction costs, and the availability of liquidity.
If costs are too high, the spread may persist longer than anticipated, creating risk for the arbitrageur. Traders must monitor the factors driving the spread to ensure it is not widening due to structural changes in the market.
Successful arbitrageurs exit their positions as the spread reaches a level that covers costs and provides a target profit. Predicting the timing of this convergence is a core challenge in quantitative finance.