Why did beach attendance drop after Jaws — a fictional film — while the actual shark-attack statistics stayed microscopic? Because the brain doesn't compute probability; it feels it — and the feeling is generated by whatever examples come to mind easily. Vivid, recent, emotional examples come easily; boring base rates don't. That's availability bias (probability = ease of recall) and its market-dominant cousin recency bias (the recent past = the expected future).
Watch the pair run a trading account:
The last trade writes the next one. Two stop-outs in a row → the next A+ setup arrives → it "feels risky" (two vivid losses are available) → you skip it or size it timidly → it works, of course. Or: three winners in a row → risk "feels" tamed → size creeps (Chapter 5's hot hand is availability wearing confidence). Your Q-bar VIX study belongs here as the antidote in miniature: feelings said low-VIX days were the comfortable ones; your own data said Low VIX was your worst regime. Availability voted comfort; the base rate voted otherwise. You've already lived this chapter and measured it.
The regime feels permanent. Six months of grinding uptrend → drawdowns become abstract, un-vivid, unavailable → hedges feel like waste, leverage feels safe, "buy the dip" hardens from tactic into law. Then one violent week makes crashes vivid again → and the crowd de-risks at the bottom, now overweighting the fresh disaster exactly as it underweighted it at the top. Entire market cycles are availability bias, breathing. (Your Legendary Traders school's Taleb chapter is the formal version: rare events are systematically underpriced because they're un-recallable until they've just happened — after which they're briefly overpriced. Note what that implies for a premium seller: your product is most overpriced right after the storm, most underpriced after long calm.)
The vivid beats the true. One friend's IPO jackpot story outweighs the base rate of IPO returns. One dramatic pharma blow-up makes the whole sector "uninvestable." News runs on vividness — which means an information diet of headlines is a probability-distorting machine pointed at your P&L.
Defense — make base rates as available as feelings. (1) Your journal is the anti-Jaws: QbarTrade's whole purpose, in this school's language, is keeping your true statistics more available than your last trade's emotion. Before skipping a setup post-stop-out, the rule is: open the stats page first — let the base rate get a vote. (2) Regime-proof the rules in advance: sizing, hedging, and drawdown protocols written during calm apply during storm because recency will argue against them precisely when they matter. (3) Age your inputs: when a vivid event drives an urge to act, impose a 24-hour rule — vividness decays fast; base rates don't.
Offense — fade the availability wave. Post-crash terror overprices protection (rich premium for sellers with pre-written risk rules); long-calm complacency underprices it (the time buyers of convexity get their bargains — Taleb's barbell, timed by the crowd's memory). And in structure terms: capitulation flushes and euphoria gaps are availability bias printing on the tape — the exhaustion gap (Market Structure school) is the moment the recent past felt most permanent to the most people.
Key Takeaway
The brain prices probability by vividness and recency, not truth — so your last trade steers your next one, and regimes feel permanent right up to their ends. Keep your journal's base rates more available than your feelings, and recognize that the crowd's freshest memory is usually its most mispriced belief.
Think About It
What does today's market consensus treat as "obviously permanent"? Whatever your answer — how much of that belief is evidence, and how much is just six months of one-directional vividness?
Mind Lab — Feeling vs. Base Rate
For two weeks, every time you feel a strong urge to skip, chase, upsize, or downsize, log two lines in QbarTrade: (1) the vivid recent event behind the feeling (be honest — there always is one), and (2) what your actual stats say about this setup/regime. At review, count how often feeling and base rate disagreed — and which one, followed, would have paid. You already know how this experiment ends; running it makes it unforgettable — which, fittingly, is how you weaponize availability against itself.