Trading Risk Modeling
The complete resource for understanding, calculating, and managing trading risk. From risk of ruin formulas to Monte Carlo simulation to position sizing strategy.
Every article, tool, and definition below is designed to answer one question: will your strategy survive long enough for your edge to play out?
Quick Answers: Trading Risk Fundamentals
What is risk of ruin in trading?
Risk of ruin is the probability that a trader will lose enough capital to stop trading. It depends on win rate, risk per trade, and risk-reward ratio. A risk of ruin below 5% is considered safe for professional trading. Calculate yours with a risk of ruin calculator.
How does Monte Carlo simulation work for trading?
Monte Carlo simulation generates thousands of randomized trade sequences using your strategy's parameters. Each sequence produces a different equity curve. The distribution reveals survival probability, expected drawdowns, and worst-case scenarios that a single backtest cannot show.
What is a safe risk per trade percentage?
Most professional traders risk 0.5–2% per trade. The optimal percentage depends on your win rate and reward-to-risk ratio. The Kelly Criterion provides the mathematically optimal size, but most traders use half-Kelly or less to reduce variance.
How many trades until a trading account blows up?
With 3% risk per trade and a 50% win rate at 1:1 R:R, roughly 25% of traders hit ruin within 200 trades. At 5% risk, that rises to over 50%. Use interactive simulations to see the exact number for your parameters.
Core Topics
Risk of Ruin in Trading
The probability of losing enough capital to stop trading. Every position sizing decision starts here.
Monte Carlo Simulation
Run thousands of randomized trade sequences to see the full distribution of outcomes, not just one backtest.
Drawdown Mathematics
Peak-to-trough decline analysis. A 50% loss needs a 100% gain to recover. The math is asymmetric.
Position Sizing Risk
How much you risk per trade matters more than when you enter. The size determines survival.
Survival Probability
Positive expected value does not guarantee survival. Variance kills accounts before edge plays out.
Interactive Tools
Risk of Ruin Calculator
Calculate your probability of ruin based on win rate, R-multiple, and risk per trade.
Strategy Playground
Run Monte Carlo simulations in your browser with custom strategy parameters.
Quant Research
Academic-style analysis of fat tails, variance, and Monte Carlo methodology.
How Traders Blow Up
Failure scenario simulations showing why even profitable strategies can blow up accounts.
Trading Risk Articles
Risk of Ruin Calculator: What Every Trader Should Know
Your win rate means nothing without knowing your risk of ruin. Here's how to calculate the probability of blowing up your account.
Position Sizing for Day Traders: The Math That Keeps You Alive
Position sizing is not about maximizing profit. It's about surviving long enough for your edge to play out.
The Probability of Blowing Up Your Trading Account
Even a strategy with a positive expected value can blow up your account. The math explains why.
Monte Carlo Backtesting: Why One Backtest Is Never Enough
Your backtest showed a 40% return. But that was one path. Monte Carlo shows the other 9,999.
How Many Trades Until Statistical Failure?
100 trades? 500? The number of trades before statistical failure depends on your edge and position size.
Expected Value vs. Survival Probability: The Trader's Dilemma
Positive EV doesn't mean you'll survive. Here's why both metrics matter and how they interact.
Why Most Retail Traders Fail (A Statistical Explanation)
The 90% failure rate in retail trading isn't about bad picks. It's about position sizing and ruin probability.
The 2% Rule vs. Actual Ruin Probability
Everyone knows the 2% rule. Few know whether it actually works for their specific strategy. Here's how to find out.
Options Trading Risk Management: The Math Behind Survival
Options add complexity to risk management. Premium, time decay, and defined risk all change the ruin equation.
Drawdown Risk Calculator: Understanding Your Worst Case
Returns tell you the best case. Drawdown analysis tells you the worst. Here's why drawdown matters more.
Risk Glossary
Risk of Ruin
The probability that a trader will lose enough capital to be unable to continue trading, calculated based on win rate, position size, and risk-reward ratio.
Kelly Criterion
A formula that determines the theoretically optimal bet size to maximize long-term growth rate, based on win probability and payoff ratio.
Monte Carlo Simulation
A computational method that runs thousands of randomized trade sequences to model the range of possible outcomes for a trading strategy, revealing best-case, worst-case, and median scenarios.
Position Sizing
The process of determining how many shares, contracts, or units to trade based on account size, risk tolerance, and the distance to a stop-loss level.
Drawdown
The peak-to-trough decline in a trading account's value, expressed as a percentage from the highest point to the lowest point before a new high is reached.
Concept Comparisons
Risk of Ruin vs. Kelly Criterion: Which Should Guide Your Position Sizing?
Risk of ruin tells you whether you'll survive. Kelly tells you how fast you could grow. Understanding both is essential for sizing positions correctly.
Monte Carlo Simulation vs. Traditional Backtesting: What Traders Miss
A backtest shows what did happen. Monte Carlo shows what could happen. The difference determines whether your strategy survives real trading.
Fixed Fractional vs. Kelly Sizing: Which Position Sizing Method Wins?
Fixed fractional is the safe default. Kelly is the theoretical optimum. Most traders should use something in between.
RangeSight Journal
I Simulated 1,000,000 Trading Strategies. Here's What Survived.
We ran one million Monte Carlo simulations across realistic retail trading parameters. The survival rate was brutal, and the patterns were not what we expected.
Trading InsightsThe Math Behind Why 90% of Day Traders Blow Up
The 90% failure rate for day traders is not a discipline problem. It is a math problem. Here is the equation that explains it.
Trading InsightsWhy Your 60% Win Rate Strategy Still Goes to Zero
A 60% win rate sounds bulletproof. Then your account drops 70% and you cannot understand why. Here is the math you were never shown.
Product UpdatesIntroducing RangeSight Studio: Monte Carlo for Every Trader
We built RangeSight because retail traders deserve the same risk analysis tools used by institutional desks.
Feature Deep DivesHow to Read RangeSight's Drawdown Curves
The drawdown curve is the most important chart in RangeSight. Here's how to read it and what to look for.
Trading InsightsWhy RangeSight Uses Real Market Volatility
A risk calculation is only as good as its volatility assumptions. Constant volatility is a dangerous simplification.
Run Full Monte Carlo Analysis
10,000 simulated paths using real historical volatility. Survival probability, drawdown curves, and P5/P50/P95 scenarios for any ticker.