E&Ps still avoiding unconventional resource plays are getting left behind, according to JPMorgan analyst Shannon Nome. "The booming popularity of unconventional 'resource play' producing assets over the past few years has been driven by North American basin maturity, rising commodity prices and falling interest rates, in our view," she says. "Virtually every top-performing E&P stock during the past three years could be characterized as a resource-play producer." She adds that having the "right" assets-long-lived reserves-in the recent investing environment has been about half the battle. "Roughly 50% of the variability in [E&P] share price can be explained solely by each company's respective reserve-to-production index." There is much more to a company's profile than its reserves-to-production index, she adds. However, "it is striking to think that at least half the battle in terms of stock-price performance has come down to nothing more than the producing characteristics of the assets."