Updated August 2026 · Mike Shell, Chief Investment Officer

Reflexivity is George Soros’s principle that investor beliefs change the fundamentals those beliefs are about. Perception and reality feed each other in a loop, which is why prices can move far past any equilibrium before reversing violently.

The thermometer is inside the room it’s measuring.

Why it matters. Conventional theory treats fundamentals as independent facts that prices approximate with varying accuracy. Soros argued the arrow runs both ways. A rising stock price lowers a company’s cost of capital, lets it raise money on better terms, fund acquisitions, and hire aggressively — which improves the fundamentals that justified the rising price. Rising home prices increase collateral values, which loosens lending, which produces more buyers, which raises prices further. In both cases the belief did not merely describe the fundamental; it altered it. That loop has no natural stopping point at fair value, which is why trends persist well beyond what any valuation model can defend and why the reversal, when it comes, is violent rather than gradual.

The framework. Soros described two functions operating simultaneously: a cognitive function, in which participants try to understand a situation, and a manipulative function, in which their actions change it. Because both run at once, neither perception nor reality is a fixed reference point. He argued market participants therefore operate under permanent fallibility — not because they are careless, but because the object they are analyzing includes their own analysis of it. The practical consequence is that reflexive processes tend to follow a shape: an initial trend, a period during which the trend and the belief reinforce each other, a moment of maximum divergence between price and underlying reality, and then a collapse that overshoots in the other direction. Nothing in that sequence produces an equilibrium.

How it’s applied in ASYMMETRY® Managed Portfolios. Reflexivity is the theoretical reason a trend-following process works at all. If prices reverted reliably to a computable fair value, following trends would be a losing strategy — reflexive feedback loops are why trends persist long enough to be captured. It also explains why the process does not forecast where a trend should stop. There is no fair value at which a reflexive move exhausts, so the discipline is participation while it runs and a predefined exit for when it turns, rather than an opinion about the level at which it becomes unjustified. The corresponding warning is about the reversal: reflexive unwinds are fast and correlated, which is why exposure has to be capable of coming down quickly rather than being defended.

Common misconceptions. Reflexivity is not the claim that fundamentals do not matter — it is the claim that they are partly endogenous, shaped by the beliefs about them, which is a narrower and stronger statement. It is not the same as a self-fulfilling prophecy, which is a one-off; reflexivity describes a continuing two-way loop. It does not apply uniformly, since the effect is strongest where price feeds directly back into the underlying business through financing, collateral, or confidence, and weakest where it does not. It is also not a timing tool: recognizing a reflexive process tells you a trend can run much further than justified, and says nothing whatsoever about when it stops. And it is criticized fairly for being hard to falsify, which is worth acknowledging — its value here is as a lens on why trends persist, not as a testable model.

Related terms. Adaptive Markets Hypothesis — the complementary evolutionary framework. Trend following — what reflexivity helps explain. Investors overreact and investor behavior — the participant side of the loop. Inflection point and asymmetric correlation follow in the lexicon. Part of the ASYMMETRY® guide to asymmetric investing.

Mike Shell is the Founder and Chief Investment Officer of Shell Capital Management, LLC, and portfolio manager of ASYMMETRY® Managed Portfolios, with nearly three decades of live-market experience across multiple full market cycles.