AXT Inc (AXTI) shares plummeted 6.78% intraday on Monday, reversing an earlier pre-market gain, as investors locked in profits following a prolonged post-earnings rally.

The sharp decline reflects concentrated profit-taking after the company's second-quarter results, reported on July 30, massively exceeded expectations. Revenue came in at $47.59 million, far above the $34.09 million consensus, while adjusted earnings per share of $0.19 beat estimates by 171%. Indium phosphide substrate revenue hit a record $30.70 million, and adjusted gross margin surged to 45.0% from just 8.2% a year earlier. The stock initially surged nearly 28% on earnings day, but subsequent sessions saw pullbacks of over 9% as traders booked gains. The current intraday reversal mirrors those prior profit-taking episodes, as short-term gains triggered renewed selling pressure.