By Jared Blikre

Alphabet (GOOGL), Microsoft (MSFT), Amazon (AMZN), and Meta (META) are all pouring more money into the physical backbone of AI — the data centers, chips, servers, and power-hungry infrastructure needed to keep the boom running.

That spending shows up as capital expenditures, or capex — Wall Street shorthand for long-term investments in the business — and it is now taking a much bigger bite out of the cash these companies generate from their day-to-day operations.

AI infrastructure is eating more of hyperscalers' cash flow · Bloomberg, Yahoo Fincance

The ramp-up is striking. Amazon is spending nearly all of its operating cash flow on capex, while Meta and Alphabet are not far behind. Microsoft is still lower, but it has been climbing too. If that ratio pushes above 100%, it means capex is bigger than the cash coming in from the core business.

That turns the AI trade into a cash-flow test. Big Tech can afford the build-out, but the question is how much cash investors are willing to see go back into the machine before the payoff becomes obvious.

Alphabet shows the trade-off most clearly.

For years, Alphabet was valued like one of the market’s great cash machines, powered by Google Search and digital ads. But its forward price-to-free-cash-flow multiple has surged above 200x, as investors pay up for AI upside while expected free cash flow gets squeezed.

Alphabet's AI rally is outrunning free cash flow. Bloomberg, Yahoo Finance

Free cash flow is the money left after a company funds the business and pays for long-term investments. In other words, it is the cash that survives the build-out.

For Alphabet, investors need that spending to start producing cash.

Jared Blikre is the global markets and data editor for Yahoo Finance. Follow him on X at @SPYJared or email him at jaredblikre@yahooinc.com.