AXT is trading 10.6% up at $77.45 after joining the S&P SmallCap 600 before the September 21, 2026, open. - Index-tracking funds are expected to buy shares mechanically, while traders may be front-running those flows. - The move is also supported by a strong semiconductor and broader-market rally, with technology stocks leading gains. - AXT is participating in Morgan Stanley’s Asia Best Corporate Day on September 21–22.