Goldman Sachs analyst Catherine O'Brien downgraded Spirit Airlines (SAVE) to Neutral from Buy and lowered her price target for the shares to $69 from $69. The analyst coupled the downgrade with an upgrade of United Continental Holdings (UAL) to Buy from Neutral. There is downside risk to the consensus earnings forecasts for Spirit while United's estimates have appropriately incorporated tougher second half 2019 comparables, O'Brien tells investors in a research note. The analyst is now less confident that Spirit's initiatives will ramp up enough in the back half of 2019 to offset the "materially tougher" comparables the company faces.