Black Friday is history. Now it’s time to welcome Cyber Monday another day of frenzied shopping and large-scale dealmaking and attempts by retailers to coax every last dollar out of your wallet. Online sales could exceed $1.5 billion today according to comScore Inc. But while shoppers spent an estimated $423 apiece from the early openings on Thanksgiving Day itself through to the end of the day Sunday up 6% from last year’s levels according to a survey conducted for the National Retail Federation investors should be cautious before they add retail stocks to their portfolios other than on a ...