QuantStreet November 2026 Letter: AI Worries

QuantStreet November 2026 Letter: AI Worries

With the one constant being that gold fell again, this time by 6.6%, October’s price action is a mirror image of what happened in markets in September. In September, tech and momentum led the charge higher, with anything value- or rate-related leading the selloff. October was the exact opposite. Utilities, financials, value, and all things rate-related had sharp rallies, while all things tech had a horrendous month, with Nasdaq down 5.3% and EM ex-China (i.e., largely Korea and Taiwan and their semiconductor sectors) down close to 10%. A broader index of international stocks did not fare very well either, seeing a drop of 3% on the month. Fixed income markets, after being positively trounced in September, had a bit of a bounce with high-yield bonds up 0.8%, investment grade and municipal bonds up 2.2% and 3.5% respectively, and medium-duration Treasuries up 2.3%.

performance

At QuantStreet, our portfolios had some bad calls and some good ones. Our small gold exposure hurt the portfolio (for the second month in a row), our international exposure did not fare well either, while our overweight in value and low-vol stocks helped (after having done poorly the month before). Overall, the portfolios performed in-line with benchmarks, with some risk levels doing worse and some doing better than their benchmarks. You can see our absolute performance numbers here. If you would like to see relative performance numbers, please email us at [email protected].

Everyone is very worried

It is telling that many of the journalists that I regularly read and respect wrote very negative pieces about the AI trade and markets more broadly in October.

Charlie Gasparino of the NY Post recently wrote about the parallels between the dot-com bubble and the AI buildout, predicting that “the correction is coming to AI.” A mid-October article from James Mackintosh of the WSJ warned that AI companies would have a hard time avoiding the overinvestment trap of prior technological revolutions. Mackintosh argues that concerns about this overbuild are leading to lower price-to-forward-earnings multiples (more on this below) as “investors are paying less per dollar of the earnings coming up in the next year, because they know it won’t last.”

Indeed, the pace of investing by the hyperscalers (Amazon, Google, Meta, Microsoft, Oracle) has been remarkable. Collectively, they’ve spent $690bn in capital expenditures (capex) over the last twelve months (LTM), with that amount representing a $334bn increase from the LTM spend from a year ago. (Interestingly, the LTM net income of these companies looks very similar to, though a bit lower than, their LTM capex. So, at least, the additional investment is of the same order of magnitude as current profits.)

capital expedenture

A more recent WSJ article from James Mackintosh talks about the “tangled web of AI bets” as one reason to be wary of the AI boom. Another WSJ piece, from Gunjan Banerji, documents how investors are looking to buy insurance against an AI selloff using either equity derivatives or credit default swaps. Boston University’s Larry Kotlikoff, in a recent Substack piece, warns about an impending stock market collapse due to AI overinvestment.

See more: The Fed Risks a Policy Error Fighting Oil Prices