Risk and position sizing
The fastest way to ruin a good edge is to bet too much on any single trade. Sizing, not stock-picking, is what keeps a strategy alive long enough to work.
A swing strategy will be wrong often — even a strong one closes a meaningful share of trades at a loss. The job of risk management is to make sure no single loss, and no short cluster of them, can take you out of the game before the edge has time to show. That means deciding in advance what fraction of the account any one trade may risk, and sizing each position to honour that cap rather than to chase the trades that feel most exciting. Sizing is the unglamorous half of trading and the half that decides whether you are still trading next year.
Two numbers do most of the work: the per-trade risk (a small, fixed share of capital) and the drawdown you are willing to tolerate before you stop and review. A strategy quoted without a drawdown figure is hiding the only number that tells you whether its returns were survivable — a headline return you could never have sat through is a return you would never actually have kept. The arithmetic that ties these together is simpler than it sounds; here it is end to end.
Illustrative figures, not advice. The point is the method, which works at any account size.
Risk cap per trade: 1% of the account → £250 at risk
Entry: 58.40 · Stop: 55.50 → stop distance = 2.90 per unit
Position size = £250 risk ÷ 2.90 distance ≈ 86 units
If the stop is hit, the loss is about £250 — the 1% you decided in advance, not a number the market chose for you.
The order of the arithmetic matters. You fix the per-trade risk first (here 1% of the account), then read the stop distance off the strategy, and the position size falls out of the two. You never start from “how many units do I want” and back into the risk — that is how a single trade ends up able to do outsized damage. A wider stop simply means a smaller position for the same fixed risk; a tighter one allows more units. The risk stays constant; only the size flexes.
How a conviction grade maps to size. Once the per-trade cap is set, the A-to-D grade tells you where, within that cap, to lean. A simple, honest mapping is to scale the risk fraction by conviction — say a full 1% on an A call, around 0.75% on a B, 0.5% on a C, and a token 0.25% or a pass on a D. Re-run the same arithmetic with the smaller risk number and the position shrinks accordingly. The grade never overrides the cap; it just decides how much of the cap a given setup has earned.
How conviction grades sharpen sizing
A flat strategy risks the same amount on every trade. A graded one can do better: it can put more weight behind its strongest calls and less behind its weakest, because it has measured which is which. On the systematic model here, the A-to-D conviction grade gives a reader a built-in sizing signal — an A call is one the strategy's own rules rate at the top of their distribution, a D one at the bottom. That does not remove the need for a position-size cap; it tells you where, within that cap, the strategy itself would lean. The grade-A bar is set per holding clock, which is why an A on the swing model means a larger typical move than an A on a faster one:
| Model | Holding clock | Grade-A bar (per trade) |
|---|---|---|
| Swing Trade | held roughly 7 to 28 days | 6.00% avg / trade |
| Multi Hour | closed within half a session to two sessions | 4.50% avg / trade |
| Day Trade | opened and closed in the same session | 0.70% avg / trade |
| Investing | carried over a long horizon | long-horizon |
An A is the top band of a model’s own measured return distribution; D is the lowest still published. Because the swing clock (7 to 28 days) lets a reversion run further than a same-session move, its grade-A bar sits around 6.00% a trade — far above the day-trade bar near 0.70% — yet both mean the same thing for their horizon. There is no E grade; it was retired so the four-step scale keeps its meaning.
What a bad version of this looks like
Teaching is only honest if it shows the failure modes, so here is what this looks like done badly — the fragile versions that quietly drain accounts:
- Sizing by excitement. Betting big on the trade that feels best and small on the rest is how one bad call undoes a good month. The setup that feels most exciting is not reliably the one most likely to work.
- No drawdown limit. Chasing the return number while never naming the peak-to-trough fall you will stop at means you only discover your real risk tolerance during the loss that breaks it.
- Risking a fixed number of units, not a fixed risk. “I always buy 100 units” means a wide-stop trade risks far more than a tight-stop one. Fix the risk first; let the size flex with the stop distance.
- Forgetting the overnight gap. A swing position is held through nights and weekends. Sizing as if the stop will always fill exactly where it sits ignores the gap risk that a day trader never carries.
None of this is complicated; all of it is easy to abandon in the heat of a live trade, which is exactly why it has to be written into the strategy rather than improvised. The edge from pillar one tells you when to act; this pillar tells you how much, and pillar three tells you where it ends. The full set of practical rules lives in the risk-management guide.