How bubbly are we?242 / 400Horsemen Index · Σ of I+II+III+IV
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Week read · Mixed

WEEK ENDING SATURDAY, OCTOBER 10, 2026

Mixed (−2): CAPE 41.87, OpenAI run-rate reset, Lipper outflow flip

How bubbly: 242/400. CAPE 41.87 and a record S&P push Overvaluation up as the 10-year reaches 5.31%; Anthropic’s Nov 9 marketing / pre-Thanksgiving calendar holds without a public S-1. OpenAI signals 2027 and its ~$50B net run-rate checks AI beliefs; Lipper flips to −$5.11B equity outflows with record bond and big money-market inflows. Mixed.

How bubbly are we?242 / 400Horsemen Index · Σ of I+II+III+IV
I Overvaluation77
II Bubble beliefs57
III Issuance60
IV Inflows48

III with megas 60without SpaceX·Anthropic·OpenAI 55

Soft −2 from Oct 3 (244): CAPE and a record S&P lift I; Anthropic’s calendar holds without a public S-1; OpenAI’s ~$50B net run-rate checks beliefs; Lipper flips back to outflows.

Overvaluation

  • ADVANCE

    Shiller CAPE ticks up to 41.87 — Multpl printed 41.87 as of Fri Oct 9, up from 41.38 a week earlier, with the S&P 500 setting a record 7,844.52 early in the week. Still the rare ≥40 regime last held for months in 1999–2000.

  • CONTEXT

    10-year Treasury closes at 5.31%, highest since 2002 — Treasury's official par curve closed the 10-year at 5.31% on Mon Oct 5 (30-year 5.66%), the highest since 2002, before easing to 5.24% by Fri Oct 9 (30-year 5.60%). Rich multiples are sitting on top of the highest discount rate in a generation.

Bubble beliefs

  • RETREAT

    OpenAI's run-rate gets marked down, and AI stocks flinch — FT/CNBC (Oct 8): end-September annualized revenue was about $50B, versus the circulated ~$68–70B that counted partner sales like Anthropic. Nvidia, Oracle and CoreWeave sank; Nasdaq 100 fell about 1.4% Thursday before partly recovering Friday — a belief reality check, not a rout.

  • MIXED

    Skeptics get louder on the Anthropic ask — New Constructs called Anthropic's ~$2T ask “the most ridiculous IPO of 2026,” and commentary is focusing on buying a mega-IPO with no public prospectus. Skepticism in print is the opposite of pure FOMO, but the deal is still racing toward November.

Issuance

  • MIXED

    Anthropic: no public S-1 yet; the clock says late October — Bloomberg’s Nov 9 marketing / pre-Thanksgiving Nov 26 trading path still stands with a confidential S-1; the 15-day public-filing rule implies a flip by about Oct 23–25. Oct 14 SF investor meetings are the next marker.

  • RETREAT

    OpenAI: 2027 listing, $30B+ private round at $1.4T — CNBC: executives signal 2027; seeking $30B or more at ~$1.4T pre-money with UAE funds including MGX in anchor talks, no term sheet yet. The 2026 revenue estimate rises to $35B from $30B; private mega capital without a public date.

    Sources
  • CONTEXT

    SpaceX lines up ~$40B of debt for Nvidia chips — FT/CNBC: SpaceX is in talks with Apollo and banks for ~$10B of loans and ~$30B of investment-grade debt to buy Nvidia chips, closing in 2027. Debt rather than equity, so it doesn't move the issuance dial, but it is the leverage version of the same AI build.

    Sources
  • ADVANCE

    The equity-supply wave gets named — Irish Times, citing GMO: buybacks reverse as hyperscalers issue for AI, mega IPOs add stock, and roughly $2T of SpaceX shares unlock by June 2027. GMO’s history suggests about 20% lower markets over 18 months from such supply; Dangote’s IPO window closes Oct 13.

Inflows

  • RETREAT

    U.S. equity funds: −$5.11B (week through Oct 7) — Lipper's first outflow in three weeks: large-caps −$14.08B, while tech sector funds still took in $4.53B. Bond funds pulled a record $19.78B and money markets $68.49B as yields hit 2002 highs. Lipper is digest color, not the IV spine.

    Sources
  • CONTEXT

    Leverage stays near records — FINRA margin debt was $1.454T in August (+37.2% YoY), just under June's record $1.502T. No new-entrant stampede this week; IV slips back.

    Sources

Horsemen Index — How bubbly are we? = I + II + III + IV (max 400). Equal-weight Lamont-hybrid; no fancy composite. Chart overall series plots Σ÷4 on the shared 0–100 axis beside the four dials. III′ (issuanceWithoutMegas) charts the non-mega track so SpaceX·Anthropic·OpenAI/≥$10B megas cannot fully hijack the main III dial. Editorial judgment—not a vendor index.

CONTEXT OVER TIME

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Toggle I–IV and the overall “How bubbly are we?” series (Σ÷4 on the shared 0–100 axis) to compare week ending 2026-10-10 against the full archive series.

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