Quantum tunneling calculus can predict a stock market crash before it even shows up in the daily trading data.
April 25, 2026
Original Paper
Multi-Scale Crash Detection via RG Flow of Instanton Action
SSRN · 6614703
The Takeaway
Theoretical physics provides a new way to see financial collapses across multiple timescales. Renormalization group flow allows researchers to detect the instanton action of a coming market break. This treats a crash like a subatomic particle escaping through a physical barrier. Traditional indicators often miss these signals because they only look at the surface-level price action. High-level physics is now being used to give banks a head start on avoiding the next global meltdown.
From the abstract
We introduce a scale-dependent crash probability model by computing the instanton action at multiple observation timescales using renormalization group (RG) flow equations for financial correlations. The Epps effect-the empirical increase of cross-asset correlations with observation timescale-modifies the double-well potential barrier in correlation space, causing the tunneling rate to vary across scales. The instanton action S(inst)(l), computed at RG scale l = log(T/Tâ), yields a "tunneling ac