Win Days % — Return
Percentage of trading days with positive return on the Return curve.
- Computed from
- Equity curve
- Scope
- Single report
- Range
- 0 – 100%
- Direction
- Higher is better
Win Days % is the share of trading days that finished in the green — that ended up, positive. It's the day-level cousin of win rate (the share of winning trades): where win rate counts profitable trades, Win Days % counts profitable days. A high value means the account closes most days higher than it opened — consistently green, day to day.
How it's calculated
Win Days % = green days / total days × 100
- green days
- days with a positive daily return (strictly > 0)
- total days
- all days in the daily series
On the Return curve, a day is green if percentage equity rose that day. Deposits and withdrawals move the curve, so a funding day can color the result.
What it tells you
| Value | Reading | Notes |
|---|---|---|
| < 40% | Mostly red days | Most days close lower — needs large green days to stay afloat. Note: trend-following and other convex strategies are *supposed* to be red most days (many small losses, rare large winners) — there it is the expected profile, not a flaw. |
| 40 – 50% | Below even | More red than green days; profitability depends entirely on green days being bigger. |
| 50 – 60% | Positive lean | A modest majority of green days — common for sound systems. Still says nothing about size. |
| > 60% | Very consistent — verify | Wins on most days. But sustained win-days above ~65–70% on a leveraged account is a warning, not a trophy: it is the grid / mean-reversion / short-volatility signature — small steady gains funded by a rare catastrophic day. Confirm green days aren’t tiny next to the red ones; cross-read [Stability (R²)](/glossary/stability). |
These bands rate frequency only. Like win rate, a high value is not automatically good: an account can be green four days out of five and still lose money if the rare red day erases a week of small gains. Always read the band next to the magnitude of green vs red days (average winning day vs average losing day).
Worked example
An account is green on 39 of 60 days — 65% Win Days %, which looks strong. But the average green day adds +0.4% while the average red day costs −1.3%. Over 60 days that nets (39 green × +0.4%) − (21 red × 1.3%) = 15.6% − 27.3% = −11.7% overall. Two thirds of days were winners and the account still lost money — the same asymmetry trap that sinks high-win-rate systems.
Pitfalls
- High % ≠ profitable. Win Days % is blind to magnitude. Many small green days and a few big red days — the classic high-win-rate losing account — can show a high value while the equity bleeds. Pair it with the average winning day vs average losing day and expectancy.
- Day-level, not trade-level. Don't confuse it with win rate: a green day can contain losing trades, and a red day can contain winning ones.
- Says nothing about size. It counts how often days are green, never how big the green or red days are. Read it with the day-magnitude metrics (average winning/losing day).
- Counted on the close. It uses each day's closing value — where the account stood at day's end — not the highs and lows in between.
- Depends on the day boundary. The daily series marks the account to market each day, so a position trader who holds for weeks generates many "days" of unrealized-P&L wiggle between a handful of actual decisions, while an intraday trader who flattens nightly has a daily series that is their realized P&L. The same Win Days % measures very different things for the two.
Win Days % vs Win Rate
Both measure "how often you win," but at different grains. Win rate is the share of trades that closed profitable; Win Days % is the share of days that finished green. They can diverge sharply: a scalper with a 70% win rate might post only 55% win days if the losing trades cluster on the same few days, or a swing trader with a 40% win rate might still close most days green because the winners are larger. Use win rate to judge trade selection, Win Days % to judge day-to-day consistency — and read both with magnitude metrics, since neither sees the size of wins versus losses.
Related
Win Rate is the trade-level sibling, Stability (R²) measures how straight the curve climbs, Expectancy folds in the size of wins and losses, and the Sharpe ratio sets return against its dispersion.