Why is stop-loss so counterintuitive: Kahneman has already provided the answer.
Author: CryptoPunk
Introduction: Systematic Self-Deception
Stop talking about technical analysis, macroeconomics, or anything else. The fundamental reason you’re still the “liquidity” being harvested is simply:
You are timid when profitable but fearless when losing.
Watching your account show a 10% unrealized gain, you panic, fearing the gains will slip away, and quickly lock in profits; watching a 30% unrealized loss, you become calm, close the software, and tell yourself: “As long as I don’t sell, it’s not a loss.”
This is not good mental state. From a cognitive science perspective, this is a form of systemic self-deception.
Nobel laureate Daniel Kahneman, in “Thinking, Fast and Slow,” has already given the verdict: your brain, in order to maintain some psychological balance, has set up a cheating “mental account” for you.
Part One: The “Downgraded” Money
Why are you reluctant to cut losses? Because you live in an illusion woven by your brain.
In the background of your mind, there are two ledgers:
- Real Account (Cash): Money used for groceries, meals, rent.
- Psychological Account (Positions): The money here is defined by you as “game tokens.”
That’s why losing 100 yuan in real life makes you upset for a long time, but witnessing tens of thousands of yuan evaporate on the trading platform leaves you indifferent. Because on a psychological level, this money has already been downgraded by you.
When your account shows a loss, your brain activates an “isolation mechanism”: as long as you don’t close the position, this loss is just pixels on the screen, “floating,” “fake.”
The difficulty of stop-loss is because it forces you to break this isolation, turning “floating loss” into “real pain.” To avoid this settlement, you choose to bury your head in the sand like an ostrich, maintaining this false psychological account without collapsing.
Wake up. In the financial world, there is no “floating loss”; every second’s market value is your current net worth. Not selling is itself a new buying decision.
(Special note: This article discusses only one core proposition—when trading is already unfavorable to you, why does human instinct push you to make worse decisions? We do not discuss fundamental reversals or systemic holdings,
only judging the irrational stubbornness based on avoidance psychology.)
Part Two: Biological Instincts When Losing
Kahneman’s prospect theory reveals a harsher truth: humans have a split attitude toward risk.
- Gained money: You become extremely risk-averse.
- Lost money: You become extremely risk-seeking.
Faced with a -20% loss, rationality tells you to cut losses and exit. But your animal instincts tell you: “Go for it! Maybe I can turn it around if I hold on a bit longer!”
Once you enter the loss zone, your brain no longer serves “maximize returns,” but “avoid admitting mistakes.”
Here, two completely different behaviors must be distinguished: one is based on pre-set rules—“strategic floating loss,” and the other is based on post-loss unwillingness—“emotional stubbornness.” This article aims to judge the latter.
In the quagmire of losses, to avoid certain damage, you are willing to stake your entire net worth on a tiny chance of breaking even. At this point, you are no longer a rational trader; biologically, you have entered a typical “loss chasing” state.
Part Three: Any Stop-Loss Requiring “On-the-Spot Choice” Is Ineffective
If you’re still thinking, “Next time I will rely on willpower to stop-loss,” congratulations, you will blow up your account again.
During adrenaline-fueled trading periods, trying to use “willpower” to fight biological instincts evolved over millions of years is itself arrogance.
Want to survive? You don’t need stronger willpower; you need a set of rules that don’t require willpower.
1. Only “hard stop-loss,” no “psychological stop-loss”
If you’re still using your brain to remember stop-loss levels, you’re leaving yourself a way out. Solution: When placing an order, always set a conditional order. Delegate the stop-loss to the exchange’s server, not your finger. If you can’t dare to set a stop-loss order, it means from the moment you open the position, you’re already prepared to be an ostrich.
2. Implement an “overnight circuit breaker”
Most big losses are caused by the obsession of “not wanting to carry losses overnight,” leading to deeper entrenchment. Solution: Set a strict rule—before market close (or before sleep), if the account is in the red, unconditionally close half of the position.
( Note: This strict rule is specifically for two types of people: 1. Subjective traders without complete backtesting; 2. Those who already show obvious emotional fluctuations during losses. Trend trading systems are not included in this discussion. )
Why is this critical? Because continuity fuels gambler psychology, and the essence of a circuit breaker is to cut off this continuity. As long as the time flow is broken, your brain can switch from “recovery mode” back to “rational mode.”
3. Redefine “Principal”
Forget your deposit amount, forget your cost basis.
Solution: Before the market opens each day, write down your current net assets on paper. This is your principal for the day. If it’s only 50,000 yuan, think in terms of a 50,000 yuan position. Never try to recover “lost money,” because that money physically no longer belongs to you.
Conclusion
The market is not only a wealth transfer arena but also a meat grinder of human nature.
Stop-loss, in essence, is an anti-human “detox” process. It goes against our innate pursuit of perfection and wounds our pride in not wanting to admit defeat.
But remember: Your brain is designed for survival, while the market is designed for harvest.
The market never rewards instinct, but it leaves a channel for the few who are willing to self-discipline.