BlackRock Says the AI Boom Is Crowding Bond Markets

BlackRock says the AI boom is still lifting U.S. stocks, even as record federal debt and a flood of data-center bonds push long yields to a 19-year high. The world’s largest asset manager is not telling clients to step aside. It is telling them the same buildout that is juicing growth is now bidding against the Treasury.

That is a stranger mix than the usual warning about an “unpredictable” outlook. The firm remains overweight U.S. equities and wants less long-term government-bond duration, because the boom and the debt are no longer separate stories.

BlackRock Is Still Long the Boom

In an Aug. 31 note titled three lessons from a tumultuous 2026, the BlackRock Investment Institute said sticky inflation, heavy government borrowing, and growing private investment needs are all pushing yields higher, and it does not see those forces letting up. Natalie Gill, a senior portfolio strategist there, and the Institute’s leadership still want risk on heading into the rest of the year.

Jean Boivin, who heads the Institute, and global chief investment strategist Wei Li have spent 2026 describing a “new regime” of scarcity in power, labor, capital, and materials. Their midyear outlook, published in June, put six linked calls on the table: AI-led growth, the cost of AI, interest rates, debt, geopolitical chokepoints, and U.S. leadership. Each call can break more than one way, which is why a static 60/40 mix is a weaker default than it was a decade ago.

We stay pro-risk with an overweight to U.S. equities, while favoring durable income and companies positioned around scarcity.

Jean Boivin, Head, BlackRock Investment Institute, Aug. 31 weekly commentary

The Institute’s tactical sheet from June already had the U.S. equity overweight next to an underweight in long Treasuries. Clients, in that framing, should collect income in short- and medium-term government paper and stop treating the long bond as automatic ballast when inflation stays sticky.

The Bond Market’s New Rival

The mechanism is uglier than “rates are high.” Government deficits usually shrink in a strong expansion, which leaves room for companies to borrow. That is not the 2026 pattern. Washington is still running a large deficit while hyperscalers sell investment-grade paper to pay for data centers, so both issuers are tapping the same pool of savings.

Tom Becker, a senior portfolio manager on BlackRock’s global tactical asset allocation team, wrote in the firm’s fall macro note that datacenter investment may be reverse crowding out government bonds. July brought the first clear indigestion, with spreads widening on hyperscaler names. In August the worry moved to government paper after the Treasury’s quarterly refunding pointed to more bill issuance into year-end.

THE YEAR THE COLLISION SHOWED UP

1. June 2026: The Institute’s midyear outlook names debt and interest rates as two of six calls investors cannot dodge.
2. July 2026: Rick Rieder, BlackRock’s global fixed income chief, publishes the capex and market-breadth figures that show how narrow the growth engine is.
3. July 2026: Hyperscaler bond spreads widen, the first open sign that buyers are choking on the speed of issuance.
4. August 2026: Treasury refunding forecasts more government supply, and the worry shifts from corporate paper to government bonds.
5. August 18, 2026: A fiscal watchdog’s tally shows the gross national debt exceeded $40 trillion for the first time.
6. August 31, 2026: The weekly note keeps the equity overweight and says long yields can still climb.

Becker’s team also flags procyclical fiscal policy in the United States, Europe, and Japan, plus the One Big Beautiful Bill Act, the Iran conflict, and tariff refunds as forces that have already lifted investment-grade issuance. The investments behind those bonds support activity and, on a short horizon, inflation, which is why the same desks stay short duration.

How High Have Yields Already Gone?

The reset is not a U.S.-only story. LSEG data cited in the Aug. 31 note show a global lift in long rates, with more than 80% of the world bond universe now yielding above 4%. Income is back. The long end is a worse hedge.

THE 2026 YIELD RESET

Global equities have returned about 10% more than three-month Treasury bills so far in 2026, while global government bonds have returned about 3% less, the Institute found. That split has become more common since the rate reset began in 2021. Rising yields mark down existing long bonds, which is why the preference is short- to medium-term government debt: income with less duration risk.

The fiscal arithmetic underneath those yields is not a BlackRock forecast. The Congressional Budget Office’s February outlook puts the 2026 deficit at $1.9 trillion and net interest at $1.0 trillion this year, rising to $2.1 trillion by 2036. In that baseline, debt held by the public at 120 percent of GDP in 2036, above the 106 percent mark of 1946, after 101 percent in 2026.

A 32-Stock Engine and a $715 Billion Bill

The growth side of the collision is real, and it is narrow. Rieder wrote in July that nominal GDP has grown at an average 5.7% annual rate over the trailing three years, 40% higher than the 2010s average. Since the end of 2024, nonresidential investment, only about 14% of GDP, has accounted for 48% of real GDP growth.

THE BUILDING BLOCKS

• Hyperscaler capex: Estimated at $715 billion in 2026 after growing more than 80% year over year.
• Chip sales: Estimated at $570 billion, with semiconductor forward earnings still climbing through shocks.
• Index math: A basket of 32 AI-related companies contributed 12.0% to year-to-date S&P 500 returns, while the rest of the index contributed -2.3%.
• Corporate paper: U.S. hyperscaler investment-grade issuance has topped $100 billion this year, more than twice the 2025 total.

Rieder’s pushback on bubble talk is the earnings line. Since October, returns in technology, semiconductors, and the Magnificent 7 have been driven more by forward earnings than by multiple expansion, and the Mag 7 forward price-to-earnings ratio had moved from 34.1 times at year-end 2025 to 25.8 times as of June 16. The Institute makes a similar point: higher rates need not kill the AI equity case if the spending keeps producing durable returns.

The next leg of the buildout still has to be absorbed. The first wave was funded by hyperscaler cash, private markets, and the strongest balance sheets in the world. OpenAI and Anthropic are now scaling multi-year compute contracts that become funding needs across equity, debt, structured products, and private markets, Rieder wrote. More cash flow is being recycled into capex instead of buybacks, dividends, or spare balance-sheet room, and more of the bill is moving into public markets through IPOs, lockup expiries, and new bonds.

Households Absorb a Rate Shock Hyperscalers Can Ignore

The same overnight rate does not land evenly. Rieder noted that the top 10 U.S. companies had a combined market value of nearly $22 trillion, equal to 86% of nominal GDP, and that their average cost of debt was 4.3%. For firms with those economics, a small move in the risk-free rate is not what decides whether to fund an AI campus. For households, small businesses, and housing, that rate is the whole story.

Credit-card delinquencies have climbed to 13.1%, against a global-financial-crisis peak of 13.7%. Real income growth has turned negative for a slice of consumers even as the top of the distribution keeps aggregate spending looking healthy. The Institute’s weekly note adds that slower labor-force growth can make a soft jobs print look like weaker demand when it is partly a supply constraint, especially with AI-related investment still supporting activity.

A company-level specimen of the labor split sits in insurance. Travelers has described its claims call-center headcount down by a third, four centers consolidated to two, and average handle time cut by more than 30%. That is the early shape of higher output with fewer people in repeatable cognitive work, while the physical buildout still needs electricians, grid crews, and contractors. The Fed funds rate is still powerful. It is just not powerful in the part of the economy that is driving this cycle.

Warsh, in the Institute’s telling, has also changed the communication mix: less forward guidance, more selective talk, and a wider toolkit that includes the balance sheet. When the data truly turns, markets may have fewer official signposts and may reprice faster. That is another reason the long bond is a smaller default hedge.

What BlackRock Wants Clients to Own Instead

As capital gets more expensive, the Institute’s second lesson is selectivity inside AI, not a blanket underweight. Cheaper open-source models are already pressing the economics of frontier large language models, which is why the note looks past the model race to the scarce inputs the buildout still has to buy.

SCARCE INPUTS THE FIRM FAVORS

• Power and grids: The physical constraint that sits in front of every new cluster.
• Chips and memory: The layer where forward earnings have kept climbing through shocks.
• Data-center infrastructure: Operators, related services, and the metal and cooling that turn power into compute.
• Short and medium Treasuries: Income with less sensitivity to the next lift in long yields.
• Credit with real protections: Cash flows, covenants, and recovery values, including infrastructure with contracted revenue.

That reading matches what the tape has already been teaching. Downstream software and levered model labs are where the financing risk concentrates as coupons rise. The bottleneck names are where scarcity still prices. After Nvidia’s latest quarter, the Nasdaq had gained 1% and sat about 3% below its record, a reminder that the equity side of the boom can keep grinding higher even as the 30-year sits near 5.21%.

Geopolitics is the third lesson, and it feeds the same rate view. The Strait of Hormuz has yet to fully reopen, U.S.-Canada trade tensions have flared again, and firms are shifting suppliers to build buffers in a more split world. Markets have been resilient to those shocks. Resilience is not the same as the risks having gone away, and fragmentation adds to scarcity of real resources and of capital.

Financing the Boom While Warning About Its Cost

On Sept. 1, BlackRock’s own account recapped the same three lessons for a wider audience: long-term government yields are here to stay, the AI theme needs a sharper filter, and geopolitical risks remain unresolved.

https://x.com/BlackRock/status/2094867088221372740

The cleaner portfolio answer is not to abandon the boom because yields have risen. It is to stop treating AI as one trade. The companies that must borrow to keep building are now part of the rate shock, and the scarce bits of the stack are the part the Institute still wants overweight. The same firm describing that split is also a major allocator to the infrastructure the split produces, which is why the collision is a positioning problem, not a press-release risk-off.

The 30-year was at 5.21% when they published. They still wanted the stocks that the spending is supposed to feed.

Disclaimer: This article is news reporting and analysis of public market commentary and official fiscal projections. It is informational only and is not investment advice, a solicitation, or a recommendation to buy or sell any security, fund, or bond. Readers should consult a qualified financial adviser or licensed investment professional who knows their objectives, time horizon, and risk tolerance before changing a portfolio. Yields, debt totals, fund positioning, and earnings figures reflect the cited BlackRock notes, Congressional Budget Office projections, and fiscal tallies as published on the dates given, and those numbers can move with new data, policy, and prices.