A strategy of buying stocks with the best history of price appreciation in recent quarters, such as Skyworks Solutions Inc. and Netflix Inc., while shorting the worst like Chesapeake Energy Corp. and Freeport-McMoRan Inc., has gained 15 percent this year, according to data compiled by Evercore ISI. Stick with your winners, goes an old Wall Street adage -- advice that is working better now than almost any time in the last quarter century.