The numbers come first. Goldman Sachs chief global equity strategist Peter Oppenheimer says the risk behind the AI boom is not a simple valuation story, but an earnings problem tied to the cost of capital.
In a note published Thursday, Oppenheimer argued that AI infrastructure spending and government borrowing are competing for the same pool of capital. Private companies are raising debt and equity to fund AI data centers, while governments are borrowing more for infrastructure, energy security and defense. He said higher energy prices are also pushing policy rates higher, adding to the strain.
Goldman’s credit team raised its full-year U.S. investment-grade issuance forecast by $200 billion, to a record $2.3 trillion. AI-related issuers now account for a quarter of that supply, according to the note. Oppenheimer also said capital spending among AA-rated technology issuers grew 65% year-over-year in the second quarter, marking the tenth consecutive quarter that aggregate AA capex growth has topped 35%.
The banker’s warning is not isolated. Five days before Oppenheimer’s report, Torsten Slok, chief economist at Apollo Global Management, argued that what used to be a 'savings glut' has turned into a 'savings shortage.' Slok said there are now more projects than capital, and that capital is competing by demanding a higher return.
He said the pressure is already visible in secondary bond markets. According to Slok, spreads on hyperscalers’ longest-dated bonds have widened, and 'most of the paper issued in 2026 trades wider today than where it priced.' He added that investors are still buying, but 'they are just charging more.'
Slok also said the competition for capital is hitting the long end of the curve, because 'data centers, power generation, transmission and government deficits are all long-duration claims on savings.'
Oppenheimer had first told clients in early August that technology stocks might not have a valuation problem, but an earnings problem. At that time, he pointed to sharp swings in quarterly earnings, Microsoft’s 17% one-day jump after strong results, Meta’s nearly 10% drop despite beating estimates, and the equal-weighted S&P 500 outperforming its cap-weighted counterpart by the widest margin since 2009.
His new report does not say the bubble definitely exists. But it tightens the case with hard numbers, a clearer mechanism and a near-term market signal already showing up in bond-market turbulence.
For investors, the message is simple: capital is not free, and the market has already started charging more for it. When AI builds demand for money at the same time governments are soaking up supply, margins and earnings no longer get a pass. That is how a boom turns into a financing problem before it turns into a headline problem.
