Data Center-Linked Stocks Shed $4.2 Trillion in Market Value Since June

Stocks tied to data-center infrastructure across manufacturing, utilities and mining have shed $4.2 trillion in market value since June, reflecting doubts about AI demand and the pace of future data-center expansion.

The decline nearly reverses half of the $9.4 trillion in value the group added over the preceding 12 months.

Comfort Systems USA, an installer of heating and cooling systems, and fiber-optics maker Corning have each fallen about 50% from earlier highs. Allient, which makes motion-control products, is down 35% from its record set in October.

Technology-stock selling and concerns about slower data-center growth have weighed on the group. Other concerns include pressure on technology companies’ cash flow from heavy AI spending, possible local restrictions on new data centers and tighter interest-rate policy.