Goldman Sachs analyst Noah Poponak downgraded Hexcel to Sell from Neutral and lowered his price target for the shares to $73 from $75. After re-rating year-to-date, the shares are the high-end of the historical valuation range, Poponak tells investors in a research note. Further, the analyst thinks an organic growth deceleration "that had previously been feared but is no longer priced in," is likely going to occur starting 2020. As a result, Hexcel shares could underperform the rest of Aerospace & Defense as growth expectations are "ratcheted down and the multiple potentially derates," says the analyst.