Two failures that feel like diligence and enthusiasm: reading only what agrees with you, and buying because the decision is being made for you by other people's excitement.
11 min read · Level 1
Most investors do not lack information; they lack any mechanism that lets information change their mind. Once a position is taken, the brain quietly reclassifies incoming facts into supporting and ignorable, and the more public the commitment the harder that classification gets. The practical answer is not to try to be less biased by willpower, which does not work. It is to build the disconfirming step into the process before the position exists, when you still have nothing to defend.
Confirmation bias is the tendency to seek, notice and believe information that supports what you already think, and to find reasons to dismiss information that does not. In investing it is unusually hard to spot, because the activity it produces looks exactly like research: you read more, you find more supporting detail, you become more confident. The volume of work goes up while the quality of the test goes down.
Fear of missing out is the companion failure at the moment of purchase. It is buying because something is rising and other people are getting richer, rather than because you have a view on what it is worth. FOMO is not impatience; it is the substitution of someone else's conviction for your own, usually at the point in a price move when the number of people who have already bought is at its highest.
Because these two do their damage precisely when the stakes are highest. Confirmation bias is strongest on positions you have already taken or publicly talked about, which are the ones where being wrong is most expensive. FOMO is strongest when prices have already risen a long way, which is when the margin of safety is thinnest. Neither of them feels like a bias in the moment - one feels like thoroughness and the other feels like decisiveness.
This is educational information, not investment, securities or financial advice. Rules differ by country and change — get advice from a qualified professional in your jurisdiction before acting.
Educational, not personalised financial advice. Nothing in the Investor Academy is a recommendation to buy, sell or hold anything — what is right for you depends on your own circumstances and the rules where you live.
Sources: U.S. SEC — Investor.gov; FINRA — Investor Insights
A pattern documented repeatedly across markets: something rises sharply, coverage of it increases, people who bought early describe their gains publicly, and the number of newcomers buying peaks near the top of the move. The 2021 episode around a handful of heavily discussed stocks and the 2000 peak in technology shares are both well-documented cases where participation was highest late and losses concentrated among those who arrived last. The people who bought late were not less intelligent. They were answering a different question - 'is this going up?' rather than 'what is this worth?' - and that question has no defence when the answer changes.
The most common self-deception is treating the amount of research done as evidence that the research was honest. Someone who has read forty enthusiastic articles about a company has not tested their view; they have rehearsed it. The test is not how much you read, it is whether any of it was capable of changing your mind - and whether you went looking for the version that would.
Before buying, write the strongest argument against the investment as if you were trying to persuade yourself out of it. If you cannot write a serious one, you do not yet understand the thing well enough to own it.
Write down, in advance, the specific observable thing that would mean your thesis has broken - a metric, a competitor move, a regulatory change. A view that nothing could falsify is a belief, not an analysis.
Deliberately read the most credible critical account you can find, and read it looking for what is right in it rather than for the flaw that lets you dismiss it.
If the reason to act now is that the price is moving, wait. Genuine opportunities that depend on acting within the hour are rare; manufactured urgency is not.
Ask plainly: could I explain why this is worth the price to someone who has never heard of it, without referring to how much it has gone up or who else owns it? If not, the conviction is not yours.
Before every purchase, and with particular care on anything you have already talked about publicly or already own - commitment makes both biases stronger.
Do not turn this into paralysis. The goal is a view that has been genuinely tested, not one that can never be acted on. At some point the disconfirming evidence has been considered and the decision has to be made.
Across well-documented episodes - the 2000 technology peak, the 2017 and 2021 cryptocurrency surges, and the 2021 activity in a small group of heavily discussed shares - the pattern of participation peaking near the top of the move and losses falling disproportionately on the most recent buyers has been recorded repeatedly by regulators and researchers.
Crowd size is not evidence. In price moves that later reversed, the crowd was largest right before the reversal, by construction.
Writing the failure case before committing - imagining the investment has already failed and explaining why - is an established technique in institutional decision-making, adopted specifically because it surfaces objections that people will not raise while a proposal is still being advocated.
Asking 'what could go wrong' invites polite answers. Asserting that it already went wrong and asking why produces real ones.
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