Bubbles require marketability money and speculation

Quinn and Turner's "bubble triangle" holds that a bubble needs three components — marketability (the oxygen: how easily the asset can be bought, sold, and divided), money and credit (the fuel: abundant capital and low yields on safe assets), and speculation (the heat: buying purely to resell at a higher price) — ignited by a spark that is either technological innovation or government policy. Applied to bitcoin, the framework is regularly invoked both ways: bitcoin is highly divisible and continuously tradeable (maximal marketability), its price history correlates with loose monetary conditions, and momentum and greater-fool trading are observable in its markets.

Nuance: The framework is descriptive and retrospective, not predictive — the authors themselves concede bubbles are identifiable with certainty only after the event, and say prediction reduces to predicting the sparks. A careful debater should also note the triangle describes conditions for any speculative boom, so it cannot by itself distinguish "bitcoin is a bubble" from "bitcoin experiences recurring speculative episodes around a persisting asset" — the historical cases in the book include both assets that vanished (Poyais bonds) and technologies that endured (railways, bicycles, radio). The divisibility point cuts both ways on stage: the same property that the book identifies as bubble oxygen is also cited as a monetary design feature.

Common misstatements: "The bubble triangle proves bitcoin is a bubble" (it identifies enabling conditions, not a verdict — the conditions are present in most liquid modern markets). "Bubbles are caused by irrational crowds" (the book treats the Mackay/mania account as the oldest but weakest explanation, emphasizing structural fuel — credit, marketability, and policy sparks — over crowd madness).