QuantStreet December 2025 Letter: Market Cycles

Markets had a mini swoon in November, on the back of AI bubble concerns (more on this below). But the recovery was quick and thus far in December tranquility has prevailed, as investors await news (later today) about the Fed.

SPX chart

A 25 basis point rate cut is widely anticipated, though Powell's remarks at the press conference will set the tone for the market (at least for a few hours). Oracle, seemingly the poster child for the levered-AI-overinvestment thesis, is reporting after the market close today, so that will be another important data point for skittish investors.

After a rough start, markets managed to eke out small gains in November, and QuantStreet did as well. You can see details about our performance here.

Angst

As a quick reminder, the prognosticators have proposed many narratives for how things might go awry in the future. Just yesterday, Howard Marks wrote in the Financial Times that the current market has bubble-like characteristics, thought he stopped short of calling it a bubble. And just this morning the Wall Street Journal warned us that "everyday investors [are] hedging against an AI bubble." In case the bubble does pop (eventually), you have been forewarned.

The longer list of concerns includes the following items, though surely some have been left out:

  • Long-term loss of reserve currency status by dollar;
  • Steepening yield curve;
  • Fiscal deficits and high government debt;
  • Start of use of leverage to finance the AI buildout;
  • Potential AI overinvestment;
  • High valuations.

We acknowledge these are legitimate longer-term issues, as we've written about in our past letters (e.g., our October 2025 letter).

However, at the risk of sounding pollyannaish, we have also pointed out multiple positives that investors should consider (see our November 2025 letter):

  • The building M&A cycle and deregulation;
  • An accommodative (perhaps overly so) Fed (e.g., potential Hassett appointment as chair);
  • Currently low corporate leverage;
  • Huge AI investment demand.

We'll learn bit more about two of these later today when the Fed announces its policy decision and when Oracle gives an update on the hyperscalers’ demand for AI infrastructure.