" When the correlation between the two temporarily weakens, i.e., one crypto moves up while the other moves down, the pairs trade would involve shorting the outperforming crypto and longing the underperforming one, betting that the "spread" between the two will eventually converge. The divergence within a pair can be caused by temporary supply/demand shifts, large buy/sell orders for one crypto, reactions to significant news about a project or company, and so on. "