If two assets are correlated and one of them moves up but not the other, you expect the return of both over a longer time period to converge, you can make a sta

If two assets are correlated and one of them moves up but not the other, you expect the return of both over a longer time period to converge, you can make a statistical arbitrage by selling the one that moved up and buying the other c.f. https://en.wikipedia.org/wiki/Pairs_trade https://en.wikipedia.org/wiki/Pairs_trade