Risk Management for Investors

Most investor education is about choosing what to buy. Rather less is about deciding how much, and what to do when a decision turns out to be wrong. That second question determines outcomes more reliably than the first, because an investor can be right most of the time and still be ruined by being badly wrong once with too much money committed.

Why this matters more than selection

Consider the arithmetic of recovery. A position that falls 20% needs a 25% gain to return to where it started. A 50% fall needs a 100% gain. A 75% fall needs a 300% gain. Losses and the gains required to reverse them are not symmetrical, and the asymmetry becomes brutal at the extremes.

This is why containing large losses matters more than capturing large gains. A portfolio that avoids catastrophic positions can survive many ordinary mistakes. One that does not may never recover from a single one.

The kinds of risk

"Risk" covers several distinct things, and they call for different responses.

• Market risk — the whole market falls. Diversifying across shares does not remove it, because they fall together.
• Company-specific risk — something happens to one business. This is the risk diversification genuinely addresses.
• Sector risk — an entire industry is affected by one development. Owning ten companies in one sector leaves you exposed to it.
• Liquidity risk — you cannot sell at a reasonable price when you want to.
• Currency risk — relevant to businesses with foreign exposure, and to the real value of your returns.
• Inflation risk — nominal returns that fail to preserve purchasing power. Cash is not risk-free in this sense.
• Concentration risk — too much in one thing, including your employer's shares alongside your salary.
• Behavioural risk — your own decisions under pressure, which for most investors is the largest of these and the least discussed.

Capacity versus tolerance

Two different questions are routinely merged.

Capacity is objective: how much loss can your circumstances absorb? Someone with secure income, no dependants and a twenty-year horizon has more capacity than someone approaching retirement with the same portfolio.

Tolerance is psychological: how much can you watch without acting badly? A person can have high capacity and low tolerance, and the constraint is whichever is lower — capacity you cannot emotionally use is not available to you.

Position sizing

The single most consequential risk decision, and the one that receives least attention. It answers: how much of the portfolio goes into this?

The principle is that no individual position should be able to cause damage you could not recover from. Many long-term investors work to an informal ceiling on any single holding, on the reasoning that any company can suffer an unforeseeable failure however sound it appeared.

No specific percentage is prescribed here, because the right figure depends on capacity, horizon and how many positions are held. What matters is that a limit exists and was decided before the position was opened rather than during it.

The corollary is uncomfortable and important: conviction is not a reason to breach the limit. The positions people size largest are the ones they are most certain about, and certainty is not correlated with being right.

Diversification, and its limits

Diversification spreads company-specific risk so that no single failure dominates. It is the closest thing to a free improvement available in investing.

But it is widely misunderstood in two directions. It does not protect against market risk — in a broad decline, most shares fall together, and investors who believed diversification would protect them are regularly surprised. And a larger number of holdings is not automatically more diversification: ten banks are one bet on banking. Genuine diversification requires holdings that respond differently to the same events, which usually means different sectors and sometimes different asset types entirely.

There is also a point beyond which adding holdings stops helping and starts hurting, because you cannot meaningfully follow fifty companies. A portfolio you cannot keep track of is not diversified, it is unmonitored.

Stop-losses and their failure modes

A stop-loss is a predetermined exit point: if the price falls to a chosen level, you sell. Its purpose is to make the exit decision in advance, in a calm moment, rather than during a decline.

The honest account of the drawbacks:

• Volatility triggers them. A stop placed close to the current price will be hit by ordinary fluctuation, taking you out of a position that then recovers.
• Gaps skip them. If a share opens far below your stop after bad news, you exit at the market price, not your level. The stop does not guarantee the price.
• Price limits can trap you. A security at its lower daily limit may have no buyers at all, so an exit may not be available that day at any price.
• They convert paper losses into realised ones. Which is the point — but it means a stop set carelessly manufactures losses that patience would not have taken.

They remain useful, particularly for shorter-term positions and for anyone who knows they struggle to sell. But they are a discipline tool, not protection, and they should be set with reference to how much the share normally moves rather than to a round number.

Liquidity risk

An underrated risk, especially in smaller listed companies. A share that trades in small volumes may be straightforward to buy in modest size and very difficult to sell in any size, particularly when you most want to.

The warning signs are visible before you buy: low average daily volume, a wide bid-ask spread, and thin quantities on either side of the quote. A wide spread is a cost you pay twice, on the way in and on the way out.

Leverage

Borrowing to invest magnifies gains and losses equally, and it introduces a risk that unleveraged investing does not have: you can be forced to sell at the worst moment because you owe money, regardless of what you think about the investment.

That forced-seller problem is what turns a recoverable decline into a permanent loss. Leverage is not a more aggressive version of the same activity — it is a different activity, and it deserves to be treated as such.

A worked example

Hypothetical, in round numbers, ignoring all taxes and charges.

An investor holds a portfolio of PKR 1,000,000 and decides in advance that no single position may exceed 10% of it, and that no single position may lose more than 2% of the total portfolio.

They identify a share at PKR 200 and decide, on their own analysis, that if it falls to PKR 160 their reasoning was wrong. That is a PKR 40 loss per share, 20% of the entry price.

• Maximum acceptable loss = 2% of 1,000,000 = PKR 20,000
• Loss per share if wrong = PKR 40
• Maximum position = 20,000 / 40 = 500 shares
• Cost of that position = 500 × 200 = PKR 100,000, which is exactly the 10% ceiling

The two rules happen to agree here. Where they disagree, the smaller number governs. Note what the arithmetic does: the exit level determines the size, rather than enthusiasm determining the size and the exit being improvised later.

These percentages are illustrative and are not a recommendation. The method — decide the exit, derive the size — is the transferable part.

The behavioural side

For most individual investors, their own behaviour is the largest single risk. A few patterns are well documented and worth recognising in yourself.

Loss aversion — losses hurt more than equivalent gains please, which leads people to hold losing positions hoping to break even while selling winners early.

Confirmation bias — seeking information that supports a decision already made, and dismissing the rest.

Overconfidence — after a run of success, which is when position sizes tend to creep up.

Herding — buying because others are, which is why the greatest enthusiasm reliably appears near the highest prices.

Anchoring — fixating on the price you paid, which the market has no knowledge of and no interest in.

Reading about these does not remove them. Writing decisions down before making them does more, because it creates a record your later self cannot quietly revise.

Reviewing a portfolio

A periodic review — quarterly or half-yearly for most long-term investors — asks a small number of questions. Has any holding grown into an outsized share of the total? Does the original reason for owning each position still hold? Has your own situation changed? Are you more concentrated in one sector than you realised?

Reviewing too often is its own risk: it encourages reaction to noise. The purpose is to check the structure, not to re-litigate every position.

Writing the rules down

Rules written in advance are worth more than intentions held in the moment, because the moment is exactly when judgement degrades.

A minimal set: the maximum size of any single position; the maximum exposure to any single sector; what would make you sell; how often you review; and what you will not do — no leverage, no acting on tips, no adding to a losing position to average down without a fresh analysis.

Written down, these are checkable. Held in your head, they will be revised precisely when they matter.

Frequently asked questions

The unglamorous part

Nobody discusses position sizing at dinner. It is, nevertheless, closer to the centre of long-term outcomes than any view about which company to buy — because it determines what a mistake costs, and everyone makes mistakes.

An investor with average selection skill and disciplined sizing will generally do better over time than one with better ideas and no limits. That is not an inspiring conclusion, but it is the one the arithmetic supports.

Continue learning

• Investment Strategies — the approaches these limits apply to.
• Fundamental Analysis — understanding what you own before sizing it.
• Risk & Regulatory Disclosures — the formal disclosures that apply to investing through us.
• Financial Glossary — definitions for the terms used above.