Risk management is the discipline of identifying what could go wrong with an investment or trade, estimating the potential loss and putting controls in place so a setback does not become a portfolio‑ending event.
It does not try to avoid all losses. It accepts uncertainty, then shapes position sizes, exit rules and portfolio mix so outcomes stay within limits you can live with.
Where loss comes from and what you can control
Markets move for many reasons, some predictable, many not. You cannot control the next headline or print on a chart, but you can control your exposure, entry and exit conditions and how much of your capital you put at risk.
- Market risk: the price of the asset moves against you. Managed with stop levels, hedging and sensible sizing.
- Concentration risk: too much tied to one idea, sector or theme. Managed with diversification and caps per asset.
- Leverage and margin risk: borrowed exposure magnifies swings and can cause forced exits. Managed by using lower leverage and wider safety buffers.
- Liquidity risk: you cannot trade at the price or size you expect. Managed by avoiding thin markets, sizing down and allowing for slippage.
- Currency risk: the FX leg moves even if the asset performs. Managed with currency hedges or local‑currency choices.
- Counterparty and operational risk: a broker, exchange or process fails. Managed with due diligence, segregation where available and backups.
Turning the idea into a plan
A practical risk plan links your goals, time horizon and tolerance for drawdowns to specific rules. It usually contains:
- Maximum portfolio drawdown: the largest fall from a peak you are willing to accept, for example 10% or 20%, which then guides risk per trade and number of concurrent positions.
- Risk per trade: a small, consistent fraction of capital at risk on any single idea, often in the region of 0.5% to 2% for active traders. Investors may size by conviction and volatility rather than a fixed percentage.
- Entry and exit rules: where you enter, where you cut a loss and where you take profits. Stop orders and alerts help, though exact order behaviour varies by provider and market conditions.
- Risk to reward: the ratio of potential gain to potential loss. Many seek setups where expected upside is at least twice the downside to help a strategy survive inevitable losing streaks.
- Review cycle: when you rebalance, reduce exposure or stand aside. This can be calendar based, risk based or event triggered.
Write the rules down. If you are trading, treat each idea as a repeatable process. If you are building a long‑term portfolio, spell out allocation ranges, rebalancing bands and what would prompt a change.
Position sizing: from stop distance to number of units
Position sizing links how wrong you can be to how much you could lose. Start with the amount you are willing to risk, then divide by the money you would lose per unit if your stop is hit.
Formula in words: position size equals money at risk per trade divided by loss per unit at the stop.
Example with shares: you have £20,000, you risk 1% per trade, so £200. A stock trades at 500p and your stop is 475p, a 25p risk per share. £200 divided by £0.25 equals 800 shares. If the stop is hit, you lose about £200 plus costs. If the distance to your stop doubles, your position halves.
This logic also works with contracts or lots. You just need the loss per unit at your stop, which may depend on the product’s tick or pip value. Knowing the size and average price of a position then makes it easier to track unrealised P&L and decide when to scale out.
Two extra checks help keep sizing realistic:
- Volatility fit: place stops outside normal noise, not right where routine swings will knock you out. If that makes risk per unit too large, either trade smaller or skip the setup.
- Portfolio overlap: several small trades in highly correlated names can behave like one very large bet. Look at sector and factor exposures, not just the count of positions.
Diversification, correlation and living with drawdowns
Diversification spreads risk across assets, sectors, styles and time. It works when exposures are not moving in lockstep. Holding cash or short‑duration instruments can also reduce overall swing.
Correlation is not fixed. Assets that usually offset each other can move together in stress. That is why many plans set a cap on total exposure to a theme, not just single lines, and keep a realistic cash buffer for opportunity and safety.
Drawdown is the fall from a high to a subsequent low. It is how most people feel risk. You can blunt drawdowns by sizing conservatively, favouring higher quality assets, using trend filters and rebalancing. Rebalancing trims winners and adds to laggards within set bands, which can limit concentration and reset risk closer to your targets.
Hedging: using options, futures and offsets
Hedging is taking a second position that tends to gain when your main exposure loses. A common approach is buying a put option to insure against a drop, or selling an index future to offset part of an equity book. Pair trades, such as long one stock and short a close peer, can reduce market direction risk and focus the bet on the spread.
Hedges have costs. Options need a premium and decay with time. Futures require margin and can introduce basis risk, where the hedge does not move exactly in line with the thing you are protecting. The aim is not to cancel all risk, it is to shape the distribution of outcomes so bad scenarios are less damaging.
Mistakes that defeat risk management
- Overexposure: a position, sector or theme that is too large for your capital or tolerance. Cap single‑name and single‑theme risk.
- Moving the stop farther away: turning a small planned loss into a large unplanned one. Pre‑define exits and stick to them unless the thesis genuinely improves.
- Adding to losers without a plan: averaging down can work in some strategies, but it raises risk. If you scale, do so by design and with limits.
- Ignoring liquidity: sizing for tight spreads that vanish in stress can backfire. Assume slippage, especially around news or out of hours.
- Too much leverage: borrowing makes even modest volatility hard to control and can force liquidations at the worst time.
- No review loop: failing to track hit rates, average win and loss, and drawdowns. A simple journal and periodic review can surface which rules are working.
Simple example of a trade plan in action
Imagine a swing trader with £50,000 who risks 1% per trade, £500. They buy a stock at £10 with a stop at £9.50, risking £0.50 per share. Position size is £500 divided by £0.50, so 1,000 shares. The first target is £11.50, three times the risk, and half the position is taken off there. The stop on the remainder is raised to entry to remove further downside. If two other trades are open in the same sector, the trader reduces new size to avoid clustering risk.
The same logic can guide long‑term investing. An investor can set allocation ranges, for example 60 to 70% equities, 20 to 30% bonds, 5 to 10% cash or alternatives, then rebalance when weights drift to the edges. They may choose to hedge a foreign holding during periods of high currency volatility, or simply accept the FX swings as part of the expected return.
Why risk management stays central
Returns are uncertain, while losses are immediate and compounding. Managing risk keeps you solvent and emotionally steady so a strategy has time to work. It lets you survive losing streaks, avoid forced sales and redeploy when opportunities appear. That, more than any one trade, is what compounds wealth over time.