Lumentum Holdings rose 9.59% and Coherent surged 6.92%, making them the two biggest gainers in the S&P 500 after the U.S. Federal Reserve (the country’s central bank) raised rates by a quarter point on the 16th. Their rally contrasted with a 0.45% decline in the S&P 500 Index and a 10-year Treasury yield above 5%, reflecting a shift within the AI hardware supply chain toward companies with confirmed orders and clearer shipment demand. Optical communications firms are benefiting from rising requirements for 800G and 1.6T products as AI clusters expand, although high rates, election-related uncertainty and data-center construction delays remain risks. Micron Technology’s earnings report at the end of the month is the next major test of AI infrastructure demand, particularly whether it continues reporting that less than half of received data-center demand has been fulfilled.