Strategy Thesis
Donchian-breakout is a classic price-channel trend follower applied to a 24-stock large-cap universe spanning technology, financials, healthcare, consumer staples, industrials, and energy. The rule is deliberately simple: buy when a stock closes at a new 20-day high, exit when it closes at a new 20-day low. No fundamentals, no sentiment — just price structure.
That simplicity is both the appeal and the limitation. The strategy is easy to reason about and hard to overfit. The tradeoff is that it will always lag turns and will struggle in choppy, mean-reverting markets.
Recent Activity
The strategy has been notably quiet over the past week. Runs from June 25 through July 2 produced zero executed trades across six consecutive sessions, with a total of nine signals rejected. Portfolio equity has nonetheless been grinding upward — from $9,488.56 on June 25 to $9,956.87 on July 2 — suggesting existing positions are doing the work.
The last cluster of executions ran in early June: long entries in KO (23 shares at $83.69), UNH (3 shares at $412.62), ABBV (11 shares at $218.75), AAPL (7 shares at $314.77), and MSFT (5 shares at $450.24). CAT was bought on June 4 at $941.58 and sold eight days later at $857.78 — a quick loss that illustrates the channel-exit discipline in action. MSFT was similarly sold at $404.21 after entry at $450.24, another whipsaw.
The current lull in signal generation is consistent with a market that has recently trended without offering clean new-high breakouts across this universe.
Backtest and Validation Performance
Over 451 days and 108 trades, donchian-breakout returned +6.95% on a starting equity of $10,000, finishing at $10,695. CAGR sits at 3.83%. Those headline numbers are modest but not alarming in isolation.
The concern is in the risk-adjusted metrics. The full-period Sharpe ratio of 0.34 is weak, and a maximum drawdown of 21.73% is substantial relative to the return produced. Win rate is 38.46% — low, but structurally expected for a trend follower where a few large winners must compensate for many small losers. With only 108 trades and $1 flat fees per trade, fee drag is negligible.
The walk-forward validation — four sequential folds — paints a more nuanced picture:
| Fold | Period | Return | Sharpe | Max DD |
|---|---|---|---|---|
| 1 | Aug 2024 – Jan 2025 | +0.73% | 0.21 | 6.71% |
| 2 | Jan 2025 – Jul 2025 | −7.46% | −1.07 | 15.58% |
| 3 | Jul 2025 – Dec 2025 | +14.09% | 2.72 | 3.14% |
| 4 | Dec 2025 – May 2026 | +11.35% | 1.86 | 6.01% |
Fold 2 was punishing — a period that likely coincided with high intramarket churn and false breakouts. Folds 3 and 4, however, are genuinely strong: back-to-back periods with Sharpe ratios above 1.8 and drawdowns under 7%.
Despite this, the strategy failed formal validation. The Probabilistic Sharpe Ratio (PSR) of 0.674 and Deflated Sharpe Ratio (DSR) of 0.198 reflect the small number of trials (6) and the performance volatility across folds. With a DSR below 0.5, the evidence that the observed Sharpe is non-zero is statistically thin.
Strengths and Risks
Strengths: The strategy's recent trajectory is encouraging. Three of four folds were profitable, and momentum has clearly improved — the last two folds outperformed the full-period average by a wide margin. The logic is clean, auditable, and not prone to overfitting.
Risks: The validation failure is not cosmetic. A 21.73% maximum drawdown with only a 6.95% total return means the strategy absorbed significant pain without proportional reward. Fold 2's −7.46% loss is a reminder of how badly channel-based systems can underperform in sideways markets. Turnover of 2,082% implies the strategy churns the book frequently, which would meaningfully erode live returns with real commissions and slippage.
The strategy is live and worth watching. But the bar for increasing position sizing or capital allocation is a sustained out-of-sample track record, not fold 3 and 4 alone.