Position Sizing Basics
Why this matters
Position size is where risk becomes real. The same chart idea is safe at one size and reckless at another.
If you pick size by gut, you are gambling. If you pick size from a risk percent and a stop distance, you are running a process.
Risk a Fixed Percent
A common starting rule: risk about 0.5%–1% of equity on a single idea (some use up to 2% with experience). That means if the stop hits, you lose that percent — not more by design.
On a $10,000 account at 1% risk, your planned loss is $100. That number drives size. Everything else follows.
- Decide % risk while calm
- Same % keeps losing streaks survivable
- Lower % while learning or in chop
Stop Distance Defines Size
Find where the idea is invalid. Measure the distance from entry to stop in price terms. Then size so that distance × size ≈ dollar risk.
Wider stop → smaller position. Tighter stop → larger position (still same dollar risk). Do not widen the stop to justify a size you already wanted.
- Dollar risk = fixed input
- Stop distance = measured from structure
- Position size = risk ÷ distance (conceptually)
Risk Box
Entry, stop, and position size forming a rectangle of fixed dollar risk.
Worked Example
Equity $10,000. Risk 1% = $100. You long SOL at $150 with a stop at $145 ($5 risk per unit).
Size ≈ $100 / $5 = 20 SOL notional units (simplified). If stop hits cleanly, you lose about $100 before fees/slippage — not an arbitrary chunk of the account.
If you wanted 100 SOL instead, you would be risking ~$500 (5%) unless you move the stop — which usually means you are cheating the process.
- Start from $ risk, not from "I like this coin"
- Fees/slippage mean live loss can exceed the plan slightly — size a bit conservatively
- Leverage is whatever is required to hold that size with your margin — not a separate ego target
Review What You Actually Risked
After the trade, compare planned risk to realized loss or win. Slippage, funding, and early exits change the number.
TrendWave’s realized PnL and trade history make it easier to see whether your sizing matched the plan instead of relying on memory.
- Planned R vs realized R
- Chronicle oversized winners/losers — they teach
- Adjust rules from data, not from one anecdote
Key Takeaways
Remember these points
- •Size from percent risk and stop distance, not gut feel.
- •Wider stops require smaller size for the same dollar risk.
- •A worked example beats a vague "don't go too big."
- •Correlated trades share risk.
- •Review realized results against the sizing plan.
Common Mistakes
Picking size first, stop second
That reverses the math and usually means the stop is wherever your pain threshold is — not where the thesis dies.
Same coin size every trade
Different stop distances need different sizes. Fixed coin amount is random risk.
Ignoring open correlated risk
Stacking similar positions quietly multiplies exposure.
Quiz
0/4 answered1.If dollar risk is fixed and stop distance doubles, position size should:
2.On a $10,000 account risking 1%, planned loss is:
3.Position sizing should start from:
4.Three correlated 1% risks can behave like:
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Related Lessons
Why Risk Management Matters
Why surviving drawdowns matters more than finding a perfect setup — risk of ruin, blow-ups, and giving your edge time to work.
Stop Losses That Make Sense
Place stops beyond structural invalidation — not at arbitrary percentages or mental levels that fail under pressure.
Discussion
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