Bill Gross, co-founder of Pimco and one of the most consequential fixed income investors in history, arrives at a stark and unambiguous conclusion in his September 30, 2026 investment outlook 1: the two pillars of the traditional portfolio are both compromised. His thesis is not built on sentiment or short-cycle data, but on something structural: the simultaneous deterioration of balance sheets across government, corporate, and personal sectors. The consequences for financial markets, in his view, are commonsensically apparent.
Credit Is the Engine. Watch the Fuel Level.
Gross opens by invoking Shakespeare's warning against borrowing, then promptly dismisses it as economically naive. "Credit expansion," he says, "is a fundamental and necessary condition to foster nominal GDP growth." He builds from Milton Friedman's money supply thesis, but goes further: the more revealing measure, in his view, is total U.S. credit across government, mortgage, and corporate segments, a figure that "is now in the vicinity of $84tn." At a current growth rate of 5.9%, that figure is barely running fast enough for an economy advancing at roughly 8% in nominal GDP terms. Gross says the system is doing just enough "to stabilise asset prices or propel them higher given AI euphoria pricing GDP growth at higher-than-historic levels." The equilibrium is fragile. "Should credit growth slow to 4 per cent or so, financial markets will probably feel the tightening."
AI Is Writing Cheques the Economy May Not Be Able to Cash
The AI investment supercycle sits at the center of Gross's concern. Hundreds of billions in hyperscaler borrowing to fund data centers represent what he describes as "anomalous" expansion by historical standards. He acknowledges the bet could pay off, but frames the downside in plain language: "Houston, we've got a problem." His most specific warning is direct: "The $1tn of AI-related investment that has been forecast for 2027 is likely to be funded by debt alone now that positive cash flow has disappeared." These are not investments funded by demonstrated returns. They are a leveraged wager on future productivity that has not yet been proven.
Government Debt: Approaching the Peacetime Ceiling
On the sovereign side, Gross is equally direct. U.S. net debt-to-GDP has reached approximately 100%, placing it at what he calls "peacetime" peak levels. Even the most optimistic observer, he says, must reckon with this. The aging population compounds the problem: boomer cohorts will cause "future social security, Medicare and Medicaid costs to swell." The generational transition that might eventually ease these burdens is, by his reckoning, "years ahead." Uneven balance sheet growth has delivered growth now, but the consequence is likely lower growth later, paired with inflation that offers little future respite absent meaningful global fiscal restraint.
The Portfolio Prescription: Preserve and Protect
Gross moves from diagnosis to prescription without hesitation. His positioning is explicit: "don't own bonds, with the exception of one-year Treasury bills, which are now at 4.55 per cent." For equities, the stance is cautious: "Be cautious with stocks at record levels as higher yields over time will contract profit margins." He adds a structural forewarning: "Be prepared for the end of 'what you are used to' stock markets and higher volatility in prices for the benchmark 10-year Treasury bonds."
Within equities, he is leery of AI hyperscalers unless their price-to-earnings ratios fall below 20, with a notable exception for Google, which trades at a 17x P/E, below the S&P average, and has consolidated within a relatively tight range for six months. Verizon and AT&T offer yields worth considering for conservative investors, though he flags competitive pressure from SpaceX's Starlink Mobile as a legitimate threat to their mobile businesses. On the income side, he highlights Nuveen Preferred & Income Opportunities Fund, trading at roughly an 8% discount to net asset value with an 11% yield, as an example of the opportunities available in closed-end funds. He also notes Pimco PDI, yielding 18% and managed by veteran managers Josh Anderson and Alfred Murata, as a higher-conviction idea. His three-word summary of the current moment: "Preserve and protect."
5 Key Takeaways for Advisors and Investors
- Credit growth is the macro variable to watch. A deceleration from 5.9% toward 4% in total U.S. credit expansion could be the catalyst for a significant repricing across equity and credit markets.
- Avoid duration. Gross's explicit recommendation against bond ownership, except for one-year Treasury bills at 4.55%, is a clear signal on where interest rate risk remains concentrated.
- AI debt expansion is not yet self-funding. The forecast $1 trillion in AI investment for 2027 is expected to be entirely debt-financed, materially raising the stakes if productivity gains fail to materialize on schedule.
- Government debt is a structural headwind. A 100% net debt-to-GDP ratio, combined with ballooning entitlement costs as the boomer cohort ages, constrains policy flexibility and long-term growth potential.
- Income at a discount is the opportunity. Closed-end funds trading below net asset value, such as Nuveen Preferred & Income Opportunities Fund, represent one of the few compelling risk-adjusted value propositions in this environment.
Footnote:
1 Gross, William H. "Don't Own Bonds and Be Cautious with Stocks." WilliamHGross.com, 30 Sept. 2026, https://williamhgross.com/dont-own-bonds-and-be-cautious-with-stocks/.
