How It Works
- Track the previous 55-bar high, the previous 20-bar low, and the 20-bar average range.
- Buy when the close breaks above the 55-bar high — the Turtle program's slower System 2, which fires rarely and only on major moves.
- Exit on whichever comes first: the close falling below the 20-bar low, or a safety stop 2 average ranges below the entry price.
Worked example. Price closes at 108, clearing the previous 55-bar high of 107.5 with an average range of 1.5 — buy with a stop at 108 − 3 = 105. Because both windows are long, the trade only ends on a deep pullback below the 20-bar low — small dips don't shake it out.
The Math Behind The Indicators
Everything runs on closing prices of the traded timeframe: P is a close, Pt today's close, and N counts bars — one bar is one candle of that timeframe, so 20 bars on a 1h chart is 20 hours.
- Price Channel (Rolling High / Low)
- The highest and lowest close over the previous N bars — the edges of the recent trading range. Closing above the channel top means price just beat every close in that window (a breakout); the channel bottom marks recent support.
- UpperN = max(Pt−1, …, Pt−N), LowerN = min(Pt−1, …, Pt−N)
- Example: If the previous 5 closes were 100, 103, 101, 102, 104, the channel spans 100 to 104. A close at 105 breaks above the top; a close at 99 breaks below the bottom.
- Average Range (ATR)
- How much price typically moves per bar. Each bar's true range is its own high-to-low span, widened if the market gapped from the previous close — so an overnight jump counts as movement even when the bar itself is small. The ATR averages the last N of them. It sizes stops: a stop placed k ATRs away automatically adapts to how volatile the market currently is.
- TRt = max(Ht − Lt, | Ht − Pt−1|, | Lt − Pt−1|), ATRN = 1NN∑i=1TRt−i+1
- Example: A bar running from a low of 99 to a high of 102 after a previous close of 100 has a true range of 3 — the high-low span, since neither gap measure beats it. If the last three true ranges were 3, 1 and 2, the 3-bar ATR is 2, so a stop 2 ATRs below an entry at 100 sits at 96.
Example Chart
Example Chart
The Metrics
| Metric | Calculation | What it shows |
|---|---|---|
| Price Change % | change = Plast − P0P0 × 100 The traded market's own close against its first close over the same window, as a percentage. | What the market did while the rule was running — the benchmark every other row here is read against. A rule that made 40% in a market that made 120% lost to doing nothing. |
| Trades | N = count(closed positions) How many positions the rule opened and closed over the window. | The sample behind every other figure, and what the fees are charged on. Two rules with the same return are not the same rule if one took nine trades and the other took nine hundred. |
| Win Rate % | W%n = winsnn × 100 Of the first n trades, how many closed above the cash they opened with after fees. Plotted trade by trade, so the line is the rate so far rather than a final figure. | How often the rule is right, which is not how much it makes. A rule can win a third of its trades and still lead, if the third it wins pays for the two it loses. |
| Cumulative P&L % | PnL%n = n∑i=1(fi − 1) × 100 Each trade's percentage result added up, net of fees. A sum rather than a compounding, so a 10% gain and a 10% loss cancel. | What the rule returned per trade, with position size taken out of it. It answers whether the edge is in the trades themselves, where the equity curve answers what the account did with them. |
| Equity | En = E0 n∏i=1fi The account compounded through every trade — the whole balance goes into the next position. Drawn net of fees as a solid line and gross of them as a dotted one. | The account itself, which is the only figure a reader actually ends up with. The gap between the two lines is what the fees took, and it widens with every trade rather than staying a fixed share. |
| Cumulative Fees | Fn = n∑i=1(Ci φ + Xi φ) Fee charged on the way into each position and again on the way out, at rate phi, on the capital actually committed — so the bill grows with the account as well as with the trade count. | The cost of trading, in the account's own units. It is the one line here that only ever rises, and the one a rule cannot trade its way out of. |
| Rolling Sharpe | Sharpet = mean(rdaily)sd(rdaily) × √365 Mean daily return over its deviation, annualized on a 365-day year because crypto has no weekend. Taken on the account marked to market every bar — open positions included, not just closed ones — and read off at each trade's exit. | Return per unit of the swing it took to get it. It is the heaviest weight in the composite score, because an account that doubled calmly and one that doubled violently are not the same result. |