The bond rout has a second engine — and it's private

Economists have spent a generation using one phrase for what happens when the state borrows too much: crowding out. Government deficits, the old story went, soak up the world's savings and starve private borrowers. This week the head of the International Monetary Fund turned the phrase inside out — and put the private borrower on the other side of the trade. Broadcom is seeking $50 billion to buy AI chips, and ten-year Treasury yields sit at 5.35%, a 24-year high ^[1].

Policymakers had a relatively easy ride over the last 17 years, as for all that time interest rates were stuck below GDP growth rates. — Kristalina Georgieva

Georgieva's coinage names something new. For most of 2025, rising government borrowing costs were a verdict on the state alone. The ten-year Treasury's term premium — the extra pay investors demand to hold long government debt — hit its highest level in months, priced on fiscal stability, macro risk and rate-path volatility ^[2]. Global yields surged on deficits, inflation and what markets called US fiscal dominance, with a $3.4 trillion deficit bill and a Moody's downgrade doing the work ^[3]. The state was the whole story. It held until the borrowers changed. In March, Amazon raised $53.8 billion — the largest corporate bond sale in history — to fund a $200 billion AI spending program, after Alphabet added $32 billion in February and Oracle planned up to $50 billion ^[4]. Tech firms have now borrowed more than $600 billion globally for AI ^[5][6]. Hyperscalers and their key suppliers together carry roughly $4.4 trillion in on- and off-balance-sheet obligations ^[7]. At that scale, officials who once spoke only of deficits began speaking of private capital. In September the European Central Bank warned that US tech debt could raise borrowing costs across the economy as Amazon, Alphabet and Microsoft approach 10% of euro-area issuance ^[8].

U.S. big tech companies could push up borrowing costs for all sectors as they accumulate debt and account for a growing share of bond markets, with a potential spillover to the sovereign and supranational segment of the bond market. — European Central Bank

One analyst put the competition in plain terms: investment-grade tech debt is now roughly 8% of all new bond issuance, and against double-digit equity returns, a five-percent Treasury has trouble competing for savings ^[9]. There is a second channel, and it runs through inflation. In August the Bank of Japan said AI-related demand exerts a sticky and lasting upward push on consumer inflation — and used it to justify raising rates ^[10]. In late August, Australia's Treasury warned that a data-center boom could reach $150 billion and raise interest rates, with tech and governments competing for limited labour, concrete and copper ^[11]. This month the Federal Reserve conceded the rate lever barely reaches AI spending at all — business computing-equipment prices rose 11.4% in one quarter, and data-center construction runs at an $85 billion annual rate ^[12]. That may leave further tightening, and the next hike, if it comes, would land on housing and autos instead. The sharpest reversal is personal. In March, Kevin Warsh — then the nominee to chair the Fed — argued that AI was a disinflationary force that could justify lower rates ^[13].

AI is a significant disinflationary force, increasing productivity and bolstering American competitiveness — Kevin Warsh

By September, under his chairmanship, the Fed had raised rates to 3.75–4% — its first hike since 2023 — resisting Treasury requests to ease, amid the very AI-driven capital demand he had read as deflationary six months earlier ^[14]. That leaves the state servicing both engines from one desk. Treasury Secretary Scott Bessent likes to say his job is selling America's debt ^[15].

As Treasury Secretary, my job is to be the nation’s top bond salesman. — Scott Bessent

His answer to the rout has been to buy the debt back instead — expanding buybacks of long-dated bonds, with more than $5 billion of ten- and twenty-year notes repurchased on September 10 — against a stated goal of keeping rates below four percent ^[14]. The ten-year broke 5% anyway, its first time since 2007 ^[14]. And some analysts read those very buybacks as an industrial policy to lower borrowing costs for AI infrastructure — the state intervening in its own bond market partly to keep funded the private race bidding up its debt ^[14]. None of this replaces the fiscal story. The same October move to 24-year highs is widely attributed to heavy government borrowing and debt-sustainability concerns alone ^[16]. Germany's bond stress has no AI driver — its €500 billion stimulus plugged budget holes amid an energy shock and an auto slump ^[17]. Australia's own treasurer, facing his Treasury's warning, blames geopolitics, fiscal worries and oil instead ^[18]. The private engine is a new layer on top of all that, not a substitute. Where the crowding shows first is where borrowing is least glamorous. Thirty-year municipal yields hit a 15-year high this month, and state and local governments have paused projects — an $1.8 billion Los Angeles convention center, a Texas toll road, work in New Jersey — waiting for the window to clear ^[19]. The fight over savings is being settled in the most ordinary places first.