We Asked GMO’s Head of Asset Allocation Why This Bubble is Easy — But Investors Will Get it Wrong
TL;DR
GMO's Ben Inker argues the current AI-driven US stock bubble is "easy" to navigate because investors can rotate to fairly priced international assets while maintaining normal risk levels, unlike the "hard" bubbles of 2007 and 2021 when all risk assets were simultaneously overvalued.
🫧 Easy vs. Hard Bubbles 3 insights
Easy bubbles permit risk-asset rotation
An "easy" bubble like 2000 or today's AI boom allows investors to avoid overvaluation by rotating to other risk assets such as small caps, REITs, or international equities while maintaining a standard 60/40 risk profile.
Hard bubbles require abandoning risk entirely
"Hard" bubbles like 2007-2008 and 2021 featured simultaneous overvaluation across all risk assets, forcing managers into cash or bonds and creating severe career risk if the bubble persisted longer than expected.
Client patience determines manager survival
Portfolios that only make sense if the bubble collapses immediately often lead to client redemptions, as investors typically fire underperforming managers and hire those riding the bubble just before it bursts.
📊 Risk-Reward Framework 3 insights
Slope indicates payment for risk-taking
The slope of the risk-reward line should normally be around 0.7, with positive slopes indicating investors are compensated for additional risk and negative slopes indicating they pay for the privilege of owning volatile assets.
2007 featured negative risk compensation
During the 2007 global bubble, the risk-reward slope turned negative for the first time, meaning every risk asset was overvalued relative to history with no diversification escape route available.
Current environment favors ex-US assets
While the current global slope has compressed to 0.1, excluding US equities reveals a 0.4 slope, indicating international and emerging markets still offer reasonable compensation for risk-taking.
💰 Earnings Bubble Characteristics 3 insights
Current bubble may be earnings-driven
Unlike the 2000 valuation bubble, today's environment resembles Europe in 2007-2008 or EM in 2012, where earnings doubled over four years due to unsustainable investment cycles before collapsing.
Massive capex creates revenue illusion
When mega-cap tech companies spend hundreds of billions on data centers, this capital expenditure flows immediately to supplier revenues without showing up as costs, temporarily inflating earnings that may not persist once depreciation begins.
Supply tsunami approaching US markets
GMO anticipates more supply entering the US stock market over the next 12 months than in living memory, which could pressure prices when the current investment boom normalizes.
🎯 Strategic Portfolio Construction 2 insights
Innovation does not guarantee investor profits
Historical evidence shows that world-changing technologies do not necessarily accrue profits to their builders, making the current AI infrastructure build-out potentially vulnerable to the fallacy that building it ensures capturing value.
Maintain normal risk through geographic shift
Investors should construct portfolios that avoid US overvaluation by owning fairly priced international risk assets rather than moving to cash, ensuring the strategy remains viable if the bubble persists longer than expected.
Bottom Line
Investors should avoid the overvalued US equity bubble by rotating into fairly priced international and emerging market risk assets rather than attempting to time the market through aggressive cash positions or derisking.
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