This section covers the part of behavioral finance concerned with how stories — not just biases or sentiment readings — set prices, and how those stories occasionally inflate into full speculative bubbles. The unifying claim, developed most prominently by Robert Shiller (Narrative Economics, 2019), is that markets are partly driven by contagious narratives that spread between participants "like an epidemic," and that financial bubbles and crashes are plausibly accounted for as primarily narrative-driven phenomena. The core tension of the whole domain is that the narrative is doing valuation work that fundamentals normally do: price comes to embed expectations of outcomes that have not happened and may never happen, sustained by belief and by the expectation of resale rather than by cash flows. That same trait can produce a story that compounds into reality (Amazon) or one that detonates (Theranos, meme-stock blowups) — and crucially, the framework is far better at recognizing the condition than at timing its end.

What this domain covers (and what it doesn't)

This section is the macro/regime-context corner of the behavioral branch — it explains why prices detach from value during speculative episodes, the recurring structure of such episodes, and the psychology that sustains them. It is deliberately descriptive and diagnostic, not signal-generating. None of these nodes is an entry setup; collectively they supply a risk-state lens.

It defers neighboring territory to its sibling sections under Behavioral Finance & Market Sentiment:

• Reflexivity (Soros) — the feedback loop by which a rising price validates a story, attracting buyers who raise the price further. This is the engine that powers narrative pricing; this section assumes it rather than re-deriving it.
• Sentiment indicators — the measurable state (put/call, AAII surveys, VIX, fund flows). Narrative dynamics is the qualitative "why"; sentiment indicators are the quantitative "how hot."
• Cognitive & emotional biases and market psychology & crowd behavior — the individual- and crowd-level mechanisms (extrapolation, representativeness, herding, FOMO) that narrative dynamics aggregate into a market-wide phenomenon.
• Contrarian signals — the tactical other side of "everyone believes the story."

The core tension: real seed, irrational extrapolation

The thread running through every node here is that bubbles almost always begin around something genuinely real — a true innovation, a real fall in rates, a real new market — which is then extrapolated far beyond what reality can support. The danger is therefore not the story's falsity (many bubble narratives are partly true) but the over-extrapolation of it: investors confuse a vivid, contagious, emotionally resonant story with a high probability of that story coming true, and they confuse a price spike with a forecast of low future returns. The measured evidence (see the children) repeatedly lands on a subtler reality than the folklore: high-narrative assets and parabolic run-ups are powerful crash-risk signals, not reliable directional sell signals — they do not, on average, earn negative returns, but they sharply elevate the probability of a large drawdown.

When it matters vs. when it doesn't

This lens earns its keep in late-cycle, euphoric, retail-broadening, high-issuance regimes — the conditions where price is visibly the story (themed manias, IPO/SPAC surges, meme episodes, high price-to-sales innovators with thin or negative earnings). It is largely irrelevant to ordinary, fundamentally-anchored markets, and it actively misleads when used as a blanket pejorative for "any expensive asset." Its single greatest weakness across all three nodes is timing: it can recognize a bubble's existence but not its peak, because irrational extrapolation can persist far longer than a skeptic's solvency. The recurring #1 misuse is treating "this looks like a bubble" as a short-the-market or all-cash trigger.

Map of the sub-topics

• Anatomy of a Bubble — the recurring structure of a speculative episode. The Minsky–Kindleberger five-stage credit cycle (displacement → boom → euphoria → distress → panic/revulsion), Minsky's hedge→speculative→Ponzi financing drift, and the empirical adjudication from Greenwood, Shleifer & You's "Bubbles for Fama" (2019): run-ups raise crash risk without, on average, lowering returns. This is the framework node.
• Greater Fool Theory — the psychological engine. Why buying a knowingly overpriced asset can be individually rational (you expect to resell to a "greater fool") yet collectively self-destructive. Includes the formal economics — Harrison–Kreps resale-option premium, Scheinkman–Xiong overconfidence-plus-short-sale-constraints — and the strong lab evidence (Smith–Suchanek–Williams) that bubbles arise even when fundamental value is known. This is the mechanism node.
• Story Stocks — the individual-security manifestation. Stocks priced on a forward narrative (disruptive tech, huge TAM, visionary founder) rather than current results. Includes Damodaran's "narrative-and-numbers" discipline (force the story into a DCF) and the academic base-rate evidence (Lakonishok–Shleifer–Vishny glamour-vs-value; Bordalo et al. diagnostic expectations) that high-expectation names underperform on average with a fat-tailed, lottery-like payoff. This is the stock-selection node.

The three nest cleanly: a story stock is the security, greater fool is why people keep paying up for it, and the anatomy of a bubble is the macro arc the whole thing follows if the story goes systemic.

Sources

• Robert J. Shiller, Narrative Economics: How Stories Go Viral and Drive Major Economic Events (Princeton University Press, 2019) — contagion/epidemic model of economic narratives; bubbles as narrative-driven. (Princeton University Press)
• Charles P. Kindleberger & Robert Aliber, Manias, Panics, and Crashes — five-stage bubble model (detailed in the Anatomy child node).
• Greenwood, Shleifer & You, "Bubbles for Fama," Journal of Financial Economics 131 (2019) — price run-ups raise crash risk without lowering average returns (detailed in the Anatomy child node).
• Aswath Damodaran, Narrative and Numbers (2017) — story-to-numbers valuation bridge (detailed in the Story Stocks child node).
• Child nodes of this section (Anatomy of a Bubble; Greater Fool Theory; Story Stocks) carry the full source lists and the precise, source-attributed statistics.

Scope note: this is a section-overview node. All quantitative claims (crash probabilities, glamour-vs-value premia, lab-bubble frequencies) and their dispute flags live in the child documents, where they are individually source-attributed; this page intentionally summarizes rather than re-asserts them.