Learn the why. Not just the what.
Investing fundamentals, market logic, and the discipline behind good decisions.
Why 'I've Held It This Long' Is Never a Good Reason to Continue
The duration of a holding period is among the least relevant pieces of information available to the investor deciding whether to continue holding a position. How long one has held something says nothing about whether it should be held going forward. Only the current investment characteristics of the position are relevant to that decision.
How Sunk Costs Trap Investors in Positions They Should Have Left
The trapping function of sunk costs in investment portfolios is not a single dramatic event but a gradual process in which the psychological cost of exiting a position grows with the size of the accumulated loss, precisely inverting the rational relationship between loss magnitude and exit urgency.
The Money Already Gone Shouldn't Decide Your Future
The sunk cost fallacy—giving undue weight to costs that have already been incurred and cannot be recovered—is responsible for an enormous amount of value destruction in investment portfolios. Its hold on investor behaviour is powerful and persistent, because sunk costs feel like real considerations even when they are formally irrelevant to any forward-looking decision.
Why You Can't Sell a Stock You've Lost 60% On
The inability to sell a position that has declined dramatically is one of the most psychologically costly features of individual investor behaviour. It is not stubbornness or irrationality in any simple sense; it is the predictable outcome of several interacting psychological forces that make the act of selling at a large loss feel fundamentally different from the act of selling at a small loss or a gain.
Why Ignoring the News Can Be a Legitimate Investment Strategy
The investor who deliberately limits her exposure to financial news is not being negligent. She is making a rational decision about the information environment she needs to implement her investment strategy effectively—a decision that the evidence supports for long-term, diversified investors who do not rely on short-term information advantages.
How Information Overload Triggers Constant Portfolio Churning
Portfolio churning—the excessive buying and selling of positions in response to information that does not actually justify the transactions—is one of the most reliably documented causes of poor investor returns. Its primary driver, in the contemporary investment environment, is not irrationality but information overload: the exposure to more market-relevant information than can be processed without generating spurious action signals.
The Noise That Masquerades as Insight in Financial Media
Financial media is extraordinarily effective at making noise look like insight. The confident tone, the specific numbers, the expert credentials, and the elaborate analytical frameworks that accompany most financial commentary create the impression of genuine knowledge where the actual predictive content is minimal.
Why More Financial News Leads to Worse Decisions
The relationship between financial news consumption and investment decision quality is negative. This is not because financial news is uniformly worthless but because the ratio of actionable signal to disruptive noise in financial media is sufficiently low that more consumption produces more noise exposure without proportional improvement in decision quality.
Why Automating Savings Removes the Worst Decision-Maker: You
The worst decision-maker available for the savings process is the human investor making real-time choices about how to allocate each dollar of income as it arrives. Real-time financial decision-making occurs in exactly the conditions—full awareness of current spending opportunities, recency bias toward recent spending patterns, susceptibility to present bias—that produce the worst outcomes.
Why the Most Informed Investors Often Perform the Worst
One of the most robust, and most practically useful, findings in behavioral finance is also one of the most counterintuitive: more information is associated with worse investment…
The Psychology Behind Why You Never Have 'Enough' Left to Invest
The investor who intends to save whatever is left over at the end of the month typically saves nothing, because there is never anything left over. This is not a consequence of insufficient income; it is a consequence of the way spending decisions are made when saving is treated as residual rather than primary.
Why Saving Feels Like Sacrifice But Isn't
The psychological experience of saving is dominated by a sense of deprivation—of forgoing current pleasures in favour of a future that is abstract and uncertain. This experience is real, but the framing that produces it is misleading. Saving is not sacrifice; it is the purchase of future optionality at a price that compounding makes extraordinarily favourable.
The Budget You Made and Never Followed
The creation of a budget is one of the most commonly undertaken and least successfully maintained financial activities available to the individual investor. The budget feels like a solution to the problem of insufficient savings; the subsequent failure to adhere to it feels like a personal failing. Both perceptions are partially wrong.
Why You Spend What You Earn No Matter How Much You Make
The elasticity of spending with respect to income is, for most people, remarkably close to one: each additional dollar of income generates approximately one additional dollar of spending. This relationship is not driven by necessity but by the psychological dynamics of consumption that operate largely independently of the absolute level of income.
Why Random Success Is the Most Dangerous Kind
A run of successful investment outcomes is always welcome. When those outcomes are the product of random variance rather than genuine skill, the welcome they receive can be actively dangerous—because random success produces the same psychological effects as skill-based success while providing none of the actual predictive power that genuine skill would imply.
How Luck Disguised as Skill Sets You Up for Disaster
The misidentification of luck as skill is one of the most consequential errors available to the investor, because it produces a positive feedback loop: lucky outcomes generate confident self-assessment, confident self-assessment generates increased risk-taking, increased risk-taking amplifies the eventual losses when luck reverses.
Why Survivorship Bias Makes Bad Strategies Look Great
Survivorship bias is the error of evaluating a strategy, an asset class, or an investment approach based on the outcomes of survivors—the funds still in operation, the strategies that produced positive returns, the investors who are publicly visible—while ignoring the much larger population of failures that has been silently removed from the data.
The Investor Who Mistook a Bull Market for Genius
A sustained bull market is one of the most effective generators of false investment confidence available. It provides years of confirming evidence for whatever strategy the investor happens to be employing, creates the impression of skill in an environment where almost any approach produces positive returns, and sets up the subsequent bear market as a devastating test of convictions that were built on inadequate foundations.
Why You Credit Skill When You Win and Blame Luck When You Lose
The asymmetric attribution of outcomes—crediting skill when investments succeed and luck or external circumstance when they fail—is one of the most reliably documented features of investor psychology. It is also one of the most consequential, because it systematically prevents the accurate assessment of one's own investment ability.
The Risk of Letting Your Identity Decide Your Portfolio
The portfolio that reflects the investor's identity—her values, her professional expertise, her cultural background, her political views—is a portfolio that has been optimised for something other than financial return. Identity-driven portfolios are comfortable to hold, easy to explain, and systematically suboptimal.
Why ESG Investing Can Become a Form of Ego Validation
The growth of ESG investing has been accompanied by a phenomenon that deserves honest examination: the use of sustainable investment labels as a form of identity signalling that serves the investor's self-image more reliably than it serves either financial returns or the environmental and social outcomes it purports to advance.
The Danger of Investing in What You Believe In
The investment portfolio is not a values statement. This is a distinction that a significant and growing number of investors resist, for understandable psychological reasons. But the conflation of investment decisions with value expression produces predictable and avoidable investment errors.
Why Your Investment Should Have No Loyalty to Any Company
Loyalty is a virtue between people. In a portfolio, it's a liability. An investor who feels loyal to a company, because she's used its products for years, admires its management…
Why You Buy Stocks You Use as a Consumer
The familiarity heuristic in investing leads individuals to favour companies whose products they personally use or whose brands they recognise. This produces portfolios that feel intuitive and comfortable but that are systematically biased in ways that have nothing to do with investment merit.