Investors’ pursuit of the companies supplying key materials to the artificial intelligence build-out is powering an epic rally in shares of chip makers. The AI trade has boosted stocks’ record run, with the S&P 500 climbing 1.5% to new highs on Wednesday after signs of progress on a Middle East peace deal and strong earnings from Advanced Micro Devices It has also sparked volatility in markets, sending investors swinging between worries that AI won’t produce the expected blockbuster profits and fears it will disrupt entire industries. Corning is among the latest companies to reap a windfall from the ripple effects of the data center build-out.