Internet stocks are down 15% since the end of February compared to a 5% rise by the S&P 500 over the same period, but they have still solidly outperformed the index if you measure from the beginning of 2013 and recent gains are making the gap even wider. While multiples remain above their post-crisis average, performance has diverged in the sector, with top performing stocks gaining 40% while the worst performing plummet just as far since February. These price dislocations create the perfect environment for stock pickers, though they will have to look at more than just growth, says Goldman…