/
© 2026 RiffOn. All rights reserved.
  1. The Memo by Howard Marks
  2. Is It a Bubble?
Is It a Bubble?

Is It a Bubble?

The Memo by Howard Marks · Dec 9, 2025

Howard Marks analyzes the AI boom, drawing parallels to past tech bubbles. While transformative, today's speculative mania likely leads to excesses.

"Circular Deals" Where AI Firms Fund Each Other Are a Key Indicator of a Bubble

The memo flags deals where money is "round-tripped" between AI players—for example, a chipmaker investing in a startup that then uses the funds to buy its chips. This practice, reminiscent of the 1990s telecom bust, can create illusory profits and exaggerate progress, signaling that the market is overheating.

Is It a Bubble? thumbnail

Is It a Bubble?

The Memo by Howard Marks·2 months ago

AI's Productivity Gains Could Be Passed to Consumers via Price Wars, Not Captured as Corporate Profits

Marks questions whether companies will use AI-driven cost savings to boost profit margins or if competition will force them into price wars. If the latter occurs, the primary beneficiaries of AI's efficiency will be customers, not shareholders, limiting the technology's impact on corporate profitability.

Is It a Bubble? thumbnail

Is It a Bubble?

The Memo by Howard Marks·2 months ago

Prudent Investing Slows Progress; Tech Revolutions Require Irrational Bubbles to Succeed Quickly

The memo argues that the "hysteria of the bubble" compresses the timeline for building out new technologies from decades into just a few years. Patient, value-focused investing would never fund the massive, parallel, and often wasteful experimentation required to jump-start a new technological paradigm at such a rapid pace.

Is It a Bubble? thumbnail

Is It a Bubble?

The Memo by Howard Marks·2 months ago

The AI Boom Is Uniquely Risky Because It's Being Financed With Debt, Not Just Equity

Unlike prior tech revolutions funded mainly by equity, the AI infrastructure build-out is increasingly reliant on debt. This blurs the line between speculative growth capital (equity) and financing for predictable cash flows (debt), magnifying potential losses and increasing systemic failure risk if the AI boom falters.

Is It a Bubble? thumbnail

Is It a Bubble?

The Memo by Howard Marks·2 months ago

The Venture Capital Playbook of One Winner Covering All Losers Is Reversed for Debt Investing

Oaktree's co-CEO highlights a critical flaw in applying venture logic to debt. In a diversified equity portfolio, one huge winner can offset many failures. In a diversified debt portfolio, the winner only pays its coupon, which is grossly insufficient to cover the principal losses from the losers.

Is It a Bubble? thumbnail

Is It a Bubble?

The Memo by Howard Marks·2 months ago

Howard Marks' Best Bubble Calls Came from Judging Investor Behavior, Not Tech Expertise

Marks emphasizes that he correctly identified the dot-com and subprime mortgage bubbles without being an expert in the underlying assets. His value came from observing the "folly" in investor behavior and the erosion of risk aversion, suggesting market psychology is more critical than domain knowledge for spotting bubbles.

Is It a Bubble? thumbnail

Is It a Bubble?

The Memo by Howard Marks·2 months ago

Tech "Inflection Bubbles" Waste Capital but Build Future Infrastructure, Unlike "Mean Reversion" Financial Fads

Howard Marks distinguishes between two bubble types. "Mean reversion" bubbles (e.g., subprime mortgages) create no lasting value. In contrast, "inflection bubbles" (e.g., railroads, internet, AI) fund the necessary, often money-losing, infrastructure that accelerates technological progress for society, even as they destroy investor wealth.

Is It a Bubble? thumbnail

Is It a Bubble?

The Memo by Howard Marks·2 months ago

"Lottery Ticket Thinking" Allows Investors to Justify Huge Valuations Based on Tiny Probabilities of Massive Success

The memo details how investors rationalize enormous funding rounds for pre-product startups. By focusing on a colossal potential outcome (e.g., a $1 trillion valuation) and assuming even a minuscule probability (e.g., 0.1%), the calculated expected value can justify the investment, compelling participation despite the overwhelming odds of failure.

Is It a Bubble? thumbnail

Is It a Bubble?

The Memo by Howard Marks·2 months ago