Hey guys thought I would try to get some feed back on the xomcvx pair I have going as I am new to pairs. The correlation is about 94.5% over a 252 day period. The "mean" is 1.005 for 252 days. The Standard deviation for 252 days is .0175 Yesterday the pair traded at a spread of .968 and two standard deviations away from the norm is .965 so I entered the trade long an equal dollar amount of XOM and short CVX as CVX was the best performer. Today, XOM reported earnings and is getting killed and CVX is also down as well but now, the spread .94 or aproximately 3 standard deviations away. My question is this, do I add another layer onto the trade and go long XOM and short CVX? In an ideal world, I want to be long CVX as that has been the better performer over time, but since the pair has deviated so much from the mean with XOM getting whacked, mean reversion suggests the pair will come back so adding another layer seems to make sense. Hoping to get some input from experienced pair traders on what to do. Thanks in advance.