Position sizing is the decision of how much to risk given entry and stop — not a formula you apply only after a winning streak. You can practise sizing on paper risk units during NSE chart replay without rupees at stake: every entry logs shares (or lots) derived from frozen rules, so you train the arithmetic and the hesitation before live capital amplifies mistakes.
Most traders size reactively: bigger after wins, smaller after fear, largest on the trade that "feels sure." Practice sizing removes the feeling and asks: given this stop distance, what size makes this exactly 1R loss if stopped — and did I take it?
Paper risk unit setup (one page, keep for 30 days)
Define:
- Practice account notional: e.g., ₹10,00,000 hypothetical (not a recommendation — any round number)
- Fixed risk per trade: e.g., 0.5% of notional = ₹5,000 = 1R
- Max daily loss: e.g., 2R — session ends on breach
- Sizing formula:
size = rupees-at-risk ÷ stop-distance-per-share
Freeze all four for the drill block. Change only between blocks, not between losses.
Size decision log (seven fields)
At each entry before next candle:
entry-price:
stop-price:
stop-distance (points):
rupees-at-risk (1R = ₹X):
computed-size (shares or lots):
size-rounded: (exchange lot rules applied?)
size-rule-followed: yes/no
If size-rule-followed is no, tag reason: oversized-confidence, undersized-fear, lot-rounding-fudge, skipped-math.
Lot size and NSE reality
Cash equity: shares in multiples you can actually trade. F&O: lot size is fixed per contract — your formula outputs contracts, floor or ceiling per written rule.
Write lot rounding rule: "Always round down to nearest lot" is conservative and practise-friendly. Rounding up "because close enough" inflates risk silently.
Illiquid names: wide spreads break sizing math. Exclude from sizing drills or tag liquidity-unrealistic.
Sizing without changing setup rules
Position sizing practice is not an excuse to loosen entries. Setup rules stay frozen from your pullback/breakout drill. Only the size column varies — and even that should vary only if your written plan includes tiered size (e.g., A-setup 1R, B-setup 0.5R).
If every trade is 1R, sizing practise is pure arithmetic under time pressure. That is valuable. Most live errors are arithmetic plus adrenaline.
Failure modes in sizing practice
- Confidence sizing — 2R risk on "best setup of the day" without written tier
- Revenge sizing — increase after loss to "get back" — violates daily max
- Ignored daily max — third -1R trade taken because market "looked hot"
- Stop moved after size locked — size no longer matches 1R
- Fantasy fills — size assumes mid-price exit on a gap through stop
Practise ending session when daily max hits — even in replay. The habit matters.
20-trade sizing drill
- Random NSE dates, liquid name, frozen setup rules.
- Every entry: complete seven-field log before reveal.
- On stop hit, log -1R (or partial if your rules allow scale-out — freeze that too).
- On daily max, stop session — log
session-cap.
Review:
- How many
size-rule-followed: no? - Did lot rounding systematically oversize?
- Did you stop at daily max or override?
Variable size tiers (advanced block)
If you use conviction tiers, define before replay:
| Tier | Condition (written) | Risk |
|---|---|---|
| A | all filters pass | 1R |
| B | one filter missing | 0.5R |
| C | skip | 0 |
Twenty decisions with tier tags. Review whether tier A was overused because you wanted larger size.
Connection to risk-reward practice
Sizing implements R design. Run risk-reward drills first (entry, stop, planned multiple), then add sizing column once stop discipline is stable. Combining everything on day one produces logs where every field is wrong.
Order: structure → stop → R plan → size → advance candle.
No live capital required — but live differences exist
Replay removes slippage emotion and margin call fear. Practice sizing still builds the habit of writing size before click. When you go live tiny, the log format stays identical — only the rupees become real.
No promise that paper sizing skill transfers perfectly. It is necessary, not sufficient.
Indian retail context
Many beginners size by "₹10,000 per trade" without relating to stop distance — same rupee risk on a 2-point stop and a 20-point stop is wildly different R. Your practice formula forces the relationship visible.
SEBI lot sizes and margin rules change. Verify current contract specs outside practice; freeze them for the block duration.
Daily loss cap in practice (non-negotiable)
If daily max is 2R, the third losing trade should not happen — even in replay. Traders treat paper caps as optional; then wonder why live caps fail. When cap hits mid-session, log remaining setup candidates as not-taken-cap and stop. Review those tags weekly: were skipped candidates genuinely valid, or were you relieved the cap gave you permission to stop?
Margin and leverage (conceptual)
MTF and F&O margin change effective size without changing stop distance. If you eventually practise derivative sizing, write margin buffer rule separately from cash 1R formula. Collapse of margin discipline is a sizing failure even when directional read was correct.
Practise position sizing in paper R-units on historical NSE charts. Join the waitlist.
Related reading
- The 300-Trade Experiment: How Much Can You Learn From 30 Days of Trading Practice?
- What Is Chart Replay? Backtesting vs Paper Trading
- Pullback vs Breakout Trading: Which Should You Practise First?
- How to Practise Stock Trading Without Losing Money
Educational note
Not investment advice. Not stock tips. Practice results do not guarantee future results.