Wall Street Sees an Earnings Bubble-And 60/40 May Be the First Portfolio to Get Rekt

Goldman and Apollo are undermining two market comfort trades at once

Two familiar Wall Street narratives are weakening together. Goldman's chief global equity strategist said the tech sector may not be a valuation bubble, but an earnings bubble. On the same day, Apollo's chief economist said the 60/40 portfolio is broken. For investors, that means the market is losing both key support stories at once: big tech can keep earning out, and bonds will cushion the downside.

The historical record on 60/40 is the softer of the two stories. Over the past 150 years, the mix suffered a more painful decline than an all-equity portfolio in one stretch of modern market history and only recovered to its previous high in June 2025. That is a problem for anyone who bought diversification expecting smaller drawdowns and a quicker recovery.

Reuters also flagged a useful stress signal: implied volatility in U.S. Treasuries rose the most since April as bonds sold off during a period when investors typically reach for safety. If equities are priced for strong execution and Treasuries stop acting like a shock absorber, the first pressure may show up in the middle of the risk spectrum, where most retail portfolios sit.

Why an earnings bubble can reverse faster than a valuation bubble

An earnings bubble can unwind more brutally than a valuation bubble because investors are no longer just paying for a future story. They are leaning on current profits as proof that the story is real. When those profits depend on a temporary balance between scarce supply and intense demand, strong results can keep reinforcing confidence until one quarter shows the cycle is peaking.

Why the AI setup feels durable

BCA's core argument is that this AI setup looks less like a pure multiple-expansion trade and more like a market where supply-demand imbalances are supporting profits. Scarcity can support pricing power, pricing power can support margins, and strong margins can justify more capex. But that loop only holds while supply remains tight relative to demand.

Why the bullish case still has substance

The bullish case is not baseless. The broader bull market has been helped by earnings growth is currently much stronger, and mega-caps have been growing into their multiples rather than simply living off narrative alone. That is why the setup is dangerous: strong fundamentals can make a fragile earnings regime look permanent right up to the point when they stop doing so.

What could break the cycle

The bearish parallel is not dot-com so much as a period when low P/E ratios masked unsustainable earnings growth. In semis and other AI-linked areas that are more cycle-sensitive, the trigger would be straightforward: new capacity arrives, scarcity fades, and the earnings-beat cycle turns into a disappointment cycle. If that happens while bonds also stop providing reliable protection, a standard balanced portfolio gets exposed much faster.

Why 60/40 is vulnerable when stocks and bonds move together

Once bond diversification starts to wobble, the problem is no longer just which equity sector is fully valued. It becomes a portfolio construction problem. The 60/40 strategy has already come through one of the worst stretches for that mix in 150 years. Now the newer concern is that bonds may not catch the knife when investors need them to.

When the hedge stops working

The mechanism is straightforward. The classic 60/40 setup works best when stocks and bonds can move in opposite directions during stress. Reuters and advisers note the stock-bond correlation tends to turn positive when inflation runs high. When that happens, Treasuries are no longer offsetting equity risk; they are adding to it. That is what bonds and stocks now often move in tandem during sharp sell-offs means for everyday portfolios.

That also changes how investors should read recent market stress. If Treasuries stop behaving like the default safety lane, then implied volatility in U.S. Treasuries rose the most since April is not just a niche macro signal. It suggests the old risk-off playbook may be getting less reliable.

Why some investors are leaning away from fixed income

This is not the same as saying bonds are useless in every downturn. Even the Reuters coverage notes Treasuries can still help in recession scenarios. But inflation, deficit pressure, and policy uncertainty have weakened their role as automatic ballast, and investors are already making more room for commodities and other inflation-sensitive assets instead of relying on fixed income for every kind of shock.

If bonds can no longer be trusted to cushion every risk-off move, capital is more likely to favor assets tied to physical scarcity and inflation sensitivity rather than defaulting to the old stock-bond split.

What a weaker 60/40 regime may look like

The practical takeaway is not to short the market on mood alone. It is to stop assuming the default mix will keep doing the job just as investors are already making more room for commodities and Treasuries are failing at a bad moment, with bonds sank across the curve during risk-off stress.

Possible portfolio responses

• Reduce automatic reliance on the 60/40 ballast and build for episodes when stocks and bonds fall together.
• Add a larger role for assets that can help when traditional fixed-income protection gets noisier.

What would support the bear case

• Leadership stays strong on fundamentals while the market keeps rewarding dominant names even as the broader backdrop gets shakier: earnings growth is currently much stronger.
• The AI earnings machine keeps printing for a while longer, feeding momentum until supply starts to catch up and unsustainable earnings growth becomes harder to ignore.

What would invalidate the call

• Fundamentals keep underpinning the rally in a durable way, which is why earnings growth is currently much stronger.
• Mega-caps keep growing into investor enthusiasm rather than relying on it, reducing the odds that the current stretch turns into a classic bubble burst.

If the "safe" sleeve stops diversifying, that is the more important break.