Risk management math you cannot skip
R-multiple, expectancy, Kelly, risk-reward ratio, equity curve. Without these, a positive-expectancy strategy can still bankrupt you through bad sizing. With them, even a marginal edge compounds.
Calmar ratio
Annual return divided by max drawdown. Simple, drawdown-focused alternative to Sharpe. Higher = better risk-adjusted return.
Equity curve
Plot of account equity over time. Shape reveals strategy character (smooth uptrend, choppy, exponential, deteriorating).
Expectancy
DeepAverage profit/loss per trade, in R-multiples. The single number that determines if a strategy is statistically profitable.
Fixed fractional position sizing
Risk the same % of current equity on every trade. Default position sizing method for most retail strategies.
Kelly criterion
DeepPosition-sizing formula maximizing long-run geometric growth. f* = (W × R - L) / R, where W = win rate, L = loss rate, R = win/loss ratio.
Max drawdown limit
DeepPre-committed maximum drawdown threshold — past which trading stops to preserve capital and re-assess strategy. The circuit breaker.
Monte Carlo simulation (trading)
Simulate thousands of possible trade orderings to bound the distribution of outcomes. Reveals tail-risk scenarios a backtest doesn't show.
R-multiple
DeepTrade outcome expressed as a multiple of initial risk (R). +2R = profit twice the initial risk; -1R = full stop. Universal trade-quality metric.
Risk of ruin
Probability that account equity falls below a critical threshold (often 50% drawdown or zero) given system stats and position sizing. The math of survival.
Risk-reward ratio (RRR)
DeepRatio of planned profit target to planned risk. 1:3 = $1 risked for $3 of target. The single most-cited but most-misunderstood trade quality metric.
Sortino ratio
Like Sharpe but only penalizes DOWNSIDE volatility. (Return - risk-free) / downside deviation. Better for asymmetric return distributions.
Trade journal metrics
Per-trade tracked metrics that reveal system character over time: R-multiple, win rate, payoff, hold time, setup type, time of day, instrument.
Ulcer Index
Drawdown-weighted volatility metric — measures pain by combining depth and duration of drawdowns. Lower is better.
Win rate vs payoff
Tradeoff between fraction of winning trades (win rate) and size of winners vs losers (payoff). High win-rate strategies usually have lower payoff; vice versa.