Thesis
Donchian Breakout is trend-following in its purest, most transparent form: buy when price prints a 20-day high, exit when it prints a 20-day low. There is no forecasting, no regime model, no discretion — just a mechanical rule that rides breakouts and cuts them when momentum reverses. It runs long-only across a 24-name universe of large-cap U.S. staples, financials, and mega-cap tech (AAPL, MSFT, NVDA, JPM, KO, XOM, and peers). The appeal is durability: this is one of the oldest systematic ideas in the book, and simplicity makes it hard to overfit.
Backtest and Validation
The full backtest returns 6.95% over 451 days (a 3.83% CAGR), ending at $10,695 from a $10,000 base. That headline hides the discomfort underneath. The Sharpe is just 0.34, the max drawdown is a steep 21.73%, and the win rate is only 38.46% across 108 trades — classic trend-following, where a few large winners must carry a majority of small losers. Turnover is heavy at 2,083%, so fees and slippage matter.
Walk-forward validation is where the picture gets interesting — and unresolved. Three of four folds were positive, and the two most recent out-of-sample windows are genuinely strong: Fold 3 returned 14.09% (Sharpe 2.72) and Fold 4 returned 11.35% (Sharpe 1.86). But Fold 2 lost 7.46% (Sharpe -1.07), and the deflated Sharpe ratio of 0.198 against a probabilistic Sharpe of 0.674 flags that, adjusted for six trials, the edge is not statistically convincing. The validation gate failed. The recent OOS strength is encouraging, but the strategy has not yet earned a clean pass.
Recent Activity
Live activity tells a quieter story. The strategy last executed trades in early-to-mid June — buys in KO, UNH, ABBV, AAPL, and CAT, plus trims in MSFT and CAT. Since then, every scheduled run from July 8 through July 15 has posted zero executions with one or two rejections, cash pinned at $1,760.89. In other words, no fresh 20-day highs have cleared the filters, and the book has been idle for over a month. Paper account value has drifted between roughly $9,863 and $9,957 — below the starting stake, reflecting a period without new breakouts to capture.
Verdict
Donchian Breakout is doing exactly what it should: sitting on its hands when no trend presents itself. The strengths are real — a simple, robust premise and two consecutive strong OOS folds. The risks are equally real — a failed validation gate, a sub-0.2 deflated Sharpe, a 22% drawdown, and a losing win rate that demands patience through long flat stretches. This is a watch, don't chase situation: promising recent behaviour, but not yet a validated edge. The next confirmed breakout, and whether the strategy can convert it, will be the tell.