Stocks rocked back and forth the flatline, torn between a rally among energy stocks and political drama in Greece. All benchmark indexes ended the day in the green. The S&P 500 added 0.26%, the Dow Jones Industrial Average edged 6 points higher, and the Nasdaq gained 0.29%. Crude oil pared earlier losses, hovering at just above $45 a barrel following reassurance from the secretary-general of OPEC that oil prices would bottom out at current levels. Among the best performers in energy, Chevron jumped 1.9% and Exxon Mobil gained 1%. National Bank of Greece tanked 8% following the Greek election.