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Risk Management
Updated 2025-06-04·Editorial policy·Trading system

What is Risk of Ruin Formula?

Classic ruin approximations combine win probability, loss probability, and risk per trade to estimate account failure odds.

Formula

RoR = ((1 − A) / (1 + A))^N

Indian market context (NSE)

Reference levels: Nifty 50 at 24,300, Reliance Industries at ₹1,300, Bank Nifty futures at 55,000 (lot size 30). Examples below show how Risk of Ruin Formula shows up on Indian index, equity, and futures books — update to live quotes in your journal.

Nifty 50 perspective

Risk of Ruin Formula on Nifty (24,300): define rupee risk per trade before the 9:15 open; index gaps on global cues can skip planned risk of ruin formula levels — use exchange-supported stop types and size for gap beyond stop.

Reliance Industries perspective

Risk of Ruin Formula for Reliance (₹1,300): stock circuits and 20% band limits can trap positions past your planned exit; keep risk of ruin formula outside circuit freeze zones where possible.

Bank Nifty futures perspective

Risk of Ruin Formula on Bank Nifty (55,000): span margin changes intraday — a valid risk of ruin formula at entry may be too large after a margin hike; recheck buying power before adding lots.

How to validate

  • Validate Risk of Ruin Formula with a written rule and at least 20 tagged examples.
  • Ask whether the reading changed because of process or one outlier trade.
  • Compare two independent time windows before adjusting position size.
  • Document validation date in weekly review notes.

How to track in TradeLyser

  • Mention Risk of Ruin Formula in trade comments when it influenced the decision.
  • Mirror the term in weekly review questions for consistency.
  • Filter trades mentioning the concept during monthly analytics.
  • Cross-link to related glossary terms in mentor notes.

Best practices

Common pitfalls

How to use this in TradeLyser

Plug tag stats into formula yearly; cap risk % if ruin odds exceed your tolerance.

Related terms

FAQ

Exact formula which variant?

Document source — Ralph Vince vs others differ.

Ruin formula for correlated trades?

Assumes independence — discount for correlation.

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