Sentiment Takes a Sharp Plunge in a Single Session

Sentiment indicators matter most for their violent swings. The Fear & Greed Index stood at 35.46 on October 29, 2026, and at 26.16 the following day. The drop reaches 9.3 points, roughly a quarter of the previous day's level. Such a move does not happen without a shift in investors' risk perception.

Its scope must nonetheless be measured. This index aggregates market measures centered on the United States: it captures the mood of US equity investors more than global conditions. Two observations do not make a trend, and that is the first limitation of this analysis.

Long-Term Rates Keep the Squeeze On

On the bond side, the euro-area benchmark remains elevated. The yield on ten-year AAA-rated debt came out at 3.37% on October 29, and the curve's level factor (Beta0) at 1.68. These values alone do not say whether rates are rising or falling, given the absence of a series in the file. They nonetheless recall that a long-term cost of capital of this order weighs on assets whose profits lie far in the future.

That is the case for artificial intelligence, where expected cash flows sit far in the future. The higher the discount rate, the more sensitive the present value of those profits is to the slightest doubt.

The AI Economy Confronts Its Own Equation

The figures published by Anthropic ahead of its initial public offering illustrate this tension. In the third quarter, ended September 30, its revenue approaches $17 billion, twelve times the prior year's level. The growth is spectacular.

It comes with a net loss of $23.3 billion, however, against $12.1 billion a year earlier. Operating expenses reach $17.5 billion, up 292%, a pace faster than that of revenue. One point remains unexplained: the gap between these expenses and the net loss, which the file does not clarify.

The mechanism is classic. A company that spends more than it earns depends on outside capital. That capital is expensive when rates are high and investors grow more selective. AI-linked stocks, which carry heavy weight in US indices, then become vectors of volatility. A decline concentrated in these names mechanically degrades momentum and market breadth, components of an indicator such as the Fear & Greed.

The file carries other warning signals, but only in headline form: a pullback in US tech stocks tied to AI spending, a $10 billion reduction in OpenAI's funding target, and the warning that Anthropic's rating may not reach investment grade after its IPO. No index figure allows the scale of these moves to be measured. These elements fit the proposed reading without proving it.

Brazil, a Shock of Another Kind

The same weekend offers an instructive counterexample. After the second round of the Brazilian election, the Ibovespa shed 18.12% over the week, its worst weekly performance since March 2020. The dollar gained 9.04% against the real, the strongest weekly rise since October 2008. Some 870 billion reais of market capitalization vanished, cutting the value of listed companies from 5.2 to 4.3 trillion.

The mechanism here is purely event-driven: after a first round judged favorable to the opposition, the market had bet on a change of power. Lula's victory, with 64.2 million votes against 59.8 million, reversed that bet. The Ibovespa had risen from 186,340 to 209,067 points in the week following the first round, before falling back to 167,922. This sequence shows that a surprise is enough to erase gains accumulated over days.

It would be excessive, however, to see in it a driver of the US Fear & Greed. This shock is local, and nothing in the file links it to the index. It illustrates instead a climate in which positions, when they are undone, unwind violently.

Capital Remains Available, but It Picks Its Targets

Another important nuance: fear has not frozen all financing channels. In solar, corporate financing reached $25.1 billion over nine months in 2026, up 45%. Debt accounts for most of it, at $20.4 billion (+61%), while venture capital falls 31%, to $2.0 billion.

This reshuffling is consistent with the thesis: when uncertainty rises, investors prefer assets backed by contractual flows over growth bets. The same sector also flags unequal access to financing, under the effect of US tax policy, trade restrictions and rising equipment costs.

What the Data Cannot Establish

Several caveats are in order. First, the series is minimal: two points for sentiment, one for rates. Second, the query on OECD indicators and complementary macro series failed, depriving the analysis of insight into the real economic cycle. Finally, the share of AI stocks in the sentiment deterioration cannot be isolated with the available elements.

It must also be kept in mind that Anthropic's growth is exceptional. Revenue multiplied by twelve is not the sign of failing demand: the doubt concerns financial balance, not usage.

A Proportionate Conclusion

The fall of the Fear & Greed to 26.16 is a real signal of nervousness, occurring in an environment of high long-term rates and questioning over AI profitability. This channel is plausible: losses that double, expenses that jump 292% and a continuous need for capital make valuations sensitive. But coincidence is not proof, and the Brazilian episode recalls that other shocks, of another nature, act in parallel.

The point to watch is simple: if sentiment stays degraded while long-term rates do not ease, the financing window for the most loss-making players could tighten. Current data do not yet establish it.

This article was written with the assistance of artificial intelligence and verified by our editorial team.