Birkenstock forecast annual profit below Wall Street expectations as the Trump administration's 15% U.S. import tariff is set to shave about 100 basis points from gross margins, following a quarter in which revenue rose 20% on a constant-currency basis to €526.3 million.Shares fell about 5% in premarket trading after the company trimmed adjusted EPS guidance to €1.90–€2.05, reaffirmed a 13–15% revenue growth outlook and plans €110–€130 million in capital spending plus a $200 million buyback while Oliver Reichert keeps a cautious, capacity-constrained growth strategy.