Shares of SolarCity (SCTY) were up more than 12% in early trading Monday, as at least four investment banks initiated coverage with bullish ratings for the solar energy system installer. Goldman Sachs (GS), Bank of America Merrill Lynch (BAC) and Needham & Co. started with buy ratings, while Credit Suisse (CS) launched its coverage with a outperform rating. Goldman, BofA and Credit Suisse were lead underwriters for SolarCity's initial public