For much of the AI boom, investors focused on the obvious winners: Nvidia Corp. (NASDAQ:NVDA) and memory-chip makers such as Micron Technology Inc. (NASDAQ:MU).

But a quieter trend has emerged over the past month.

Some of the biggest stock-market winners have been a group of former 1990s technology titans once associated with PCs, networking equipment and enterprise hardware.

Dell Technologies Inc. (NYSE:DELL) and Hewlett Packard Enterprise Co. (NYSE:HPE) have roughly doubled in a month. 

Cisco Systems Inc. (NASDAQ:CSCO) and International Business Machines Corp. (NYSE:IBM) have both risen by 40%.

The common denominator is artificial intelligence infrastructure.

Dell Showed How Fast The Demand Is Compounding

The market’s sudden enthusiasm for Dell and HPE stems from a simple realization: building AI requires far more than chips.

Think of the artificial intelligence boom as a new kind of factory. The chips from Nvidia Corp. (NASDAQ:NVDA) are the engines. But an engine alone moves nothing.

It needs a chassis, wiring, cooling and a power supply. In the data center those are the servers, ...