Oil pump jacks operate at dusk. Apu Gomes/AFP via Getty Images Energy stocks used to make up more than 10% of the S&P 500. But last year they fell below 3%. Some fund managers abandoned the sector altogether, given that it has underperformed the broader market consistently over the past decade. Why put 2% of your portfolio in energy, when you can just add another 2% of That underweighting in energy, however, may suddenly shift in 2021, some analysts are predicting. Oil suddenly looks like a decent bet, given that Saudi Arabia has signaled that it will backstop the price by curbing production. U.S. producers, meanwhile, are being prudent with their cash.