Positions & Risk
Basic4 Min Read
Risk Management: How Much, When
The one skill that decides not whether you win, but whether you stay in the game.
A beginner asks "what should I buy?" Someone who has survived a long time asks "how much should I buy?" The second question is less exciting, and it determines more of the outcome.
The Math of Asymmetry
Losses are not symmetric. The percentage you lose and the percentage you need to get back to even are not the same number:
The Rally Needed to Break Even
This table alone explains why risk management is a necessity, not a preference. Keeping small losses small is easier than finding big winners — and contributes more to the result.
How Position Size Is Calculated
Professionals don't think in "how many shares." They go in this order:
- Decide what percent of your capital one idea may cost you. A common rule: never risk more than 1–2% of the total on a single idea.
- Decide where you'll admit you were wrong. That is the stop level.
- Divide the two.
That distinction is critical: position size and risk are not the same thing. Risk is the position size multiplied by the stop distance.
What Sets the Stop Distance
Not a round number — the stock's own character. Putting a 2% stop on a stock that swings 4% on an average day means "take me out of the market on an ordinary day." A volatile stock needs a wider stop and a smaller position. More: What Is Volatility?
The Four Common Mistakes
| Mistake | Why It's Wrong |
|---|---|
| Moving the Stop Down After a Drop | Handing the decision to fear. The loss no longer has a limit. |
| Adding to a Losing Position | Putting more money on the wrong idea. The average falls, the risk grows. |
| Closing Winners Early, Losers Late | Small profits, big losses. It runs the table above in reverse. |
| Concentrating in One Idea | One mistake can take half the capital. |
Planning to Lose
A good investor answers three questions before opening a position:
- If I'm wrong about this idea, how will I know?
- If I'm wrong, how much do I lose?
- When that loss happens, will I lose sleep?
If the answer to the third is "yes," the position is too big. That criterion is practical, not mathematical — and it is the most reliable one.