The relative value arbitrage rule ("pairs trading") is a well-established speculative investment strategy on financial markets, dating back to the 1980s. Based on relative mispricing between a pair of stocks, pairs trading strategies create excess returns if the spread between two normally comoving stocks is away from its equilibrium path and is assumed to be mean reverting. To overcome the problem of detecting temporary in contrast to longer lasting deviations from spread equilibrium, this paper bridges the literature on Markov regime-switching and the scientific work on statistical arbitrage.

Keywords: statistical arbitrage, pairs trading, mean reversion, Markow regime switching

Continue reading here.