Learn the why. Not just the what.
Investing fundamentals, market logic, and the discipline behind good decisions.
Timeframes and Self-Similarity: Why the Same Patterns Appear at Every Scale
A price chart of a single day and one of a decade can look strikingly alike. That resemblance isn't coincidence, and it has real consequences for how markets should be read.
Volatility Is Not Risk: A Distinction That Changes Everything
Volatility measures how much a price moves. Whether that movement amounts to risk depends on something volatility itself can't tell you: how long you actually plan to hold.
What a Share Price Actually Represents
A price isn't a measurement of what something is worth. It's a record of what one buyer and one seller managed to agree on, in the last moment they agreed on anything.
Who Is on the Other Side of Your Trade
Every purchase needs a seller. Before congratulating yourself on an insight, it's worth asking who took the other side, and why.
Why a Company Can Report Excellent Results and Fall
A company posts record profits and its stock drops. Nothing has gone wrong. The market wasn't reacting to the profits, it was reacting to the gap between the profits and what everyone…
Why Markets Are Hard to Beat: The Competition You Cannot See
When you buy because you think something is cheap, someone else is selling because they think it is dear. The uncomfortable question is what that someone knows that you do not.
Buy-and-Hold: The Underrated Power of Doing Less
Buy-and-hold sounds trivial until you try it: the whole method rests on doing the one thing investors are worst at, which is nothing.
Contrarian Investing: The Discipline of Standing Apart
The contrarian doesn't disagree with the crowd for the pleasure of disagreeing. They disagree because the crowd, at moments of extremity, has demonstrably been wrong before.
Core-Satellite: Structuring a Portfolio Around Conviction
Core-satellite lets you hold two contradictory impulses at once: the discipline to own the market broadly and cheaply, and the itch to bet on what you actually believe.
Dollar-Cost Averaging: Turning Time Into an Edge
Investing a fixed sum at regular intervals sounds almost too plain to count as a strategy. Its power lies not in what it achieves but in what it prevents.
Factor Investing: The Building Blocks Behind the Styles
Strip away the labels of value, growth, and momentum, and what's left is a colder, more measurable way of asking the same questions.
Index Investing: The Case for Owning Everything
Index investing starts with an admission most investors find hard to make: picking the winners ahead of time is far harder than just owning all of them.
Momentum Investing: Riding Strength Without Chasing Noise
Momentum rests on an uncomfortable observation: assets that have performed well recently have often kept performing well, for reasons nobody can fully explain.
Quality Investing: Why Durable Businesses Compound
Ask what makes a business good, and whether goodness can be trusted to last, and you have the entire quality investing thesis in one deceptively simple question.
The Tail Risk You Keep Dismissing Until It Destroys You
Tail risks—the low-probability, high-consequence events that occupy the extremes of the return distribution—are systematically underweighted by individual investors. The underweighting is not random; it follows from the same psychological mechanisms that make everyday risk assessment comfortable and that make extreme risk assessment systematically optimistic.
Why Backtesting Feels Safer Than It Actually Is
Backtesting—the evaluation of an investment strategy against historical data to assess its past performance—is one of the most widely used and most systematically misinterpreted tools in investment analysis. A strategy that performs well in backtesting is not demonstrated to be a good strategy; it is demonstrated to be a strategy that would have performed well in the specific historical period tested.
The Danger of Risk Tolerance Surveys You Fill Out in Bull Markets
Risk tolerance is not a stable characteristic. It varies systematically with market conditions, recent portfolio performance, and the emotional state of the investor at the moment of assessment. Risk tolerance surveys administered during bull markets consistently overestimate the investor's genuine capacity to sustain losses without changing strategy.
Why You Don't Truly Understand the Risk You're Taking
Most investors have a stated risk tolerance that significantly exceeds their revealed risk tolerance—the risk tolerance they actually demonstrate when markets decline and the abstract acceptance of risk confronts the concrete reality of losses. This gap between stated and revealed risk tolerance is one of the most consequential in personal finance.
Why You Need a Financial Advisor Who Will Tell You What You Don't Want to Hear
The financial advisor who tells the client what she wants to hear is providing a service that feels pleasant and is financially dangerous. The advisor who tells the client what she needs to hear—even when what she needs to hear is uncomfortable—is providing a service that may feel unpleasant and is financially valuable.
The Conflict of Interest Hidden Inside Every Financial Recommendation
Every financial recommendation exists within an incentive structure that shapes its content in ways that are not always transparent to the recipient. Understanding these incentive structures is not an exercise in cynicism; it is a necessary precondition for evaluating the advice one receives with appropriate calibration.
Why 'My Friend Made a Fortune on This' Is Never a Sound Strategy
The anecdote of a friend or acquaintance who made a fortune on a particular investment is one of the most compelling and least reliable inputs to investment decision-making. Its compellingness derives from the social proof it provides and the vividness of the specific example; its unreliability derives from the fact that it is a single data point drawn from a population whose full distribution the investor never sees.
The Guru Who Was Right Once and Wrong Every Time After
The investment guru phenomenon—the elevation of a particular analyst, commentator, or investor to the status of reliable oracle on the basis of one or a small number of spectacular correct calls—is one of the more expensive cognitive errors available to the individual investor. It conflates the occurrence of a correct prediction with the existence of genuine predictive ability.
Why You Take Investment Tips From People With Nothing to Lose
The investment advice that circulates most freely is almost always the advice that costs its source nothing to give. The colleague who enthusiastically recommends a stock has no financial stake in whether the recommendation proves correct. The financial commentator who predicts a market rally suffers no consequence if the rally fails to materialise. The asymmetry between the cost to the advice-giver and the cost to the advice-receiver is the central fact that should govern how investment tips are evaluated.
The Psychological Pain of Selling at a Loss (and Why You Must)
Selling at a loss is one of the most psychologically costly actions available to the individual investor, and one of the most financially necessary. The pain it produces is real, not merely perceived—it involves the crystallisation of failure, the repudiation of prior judgment, and the permanent elimination of the recovery option that continued holding preserves.