Does the Bollinger Band Reversion strategy beat buy & hold on Tech Sector ETF (XLK)? (XLK · backtested honestly)
Bollinger Bands sit a number of standard deviations around a moving average. Buy when price closes below the lower band (statistically stretched down) and exit when it reverts to the middle band. Mean-reversion; a hard stop caps the trades where price keeps falling.
Over this period, Bollinger Band Reversion on Tech Sector ETF (XLK) returned +47.6%, while simply buying and holding returned +149.0% — it lagged buy & hold by 101 points, with a worst drawdown of -14.4%. It traded 23 times and sat in cash about 82% of the time. It's a mechanism you test — not a recommendation.
That's the past — settled, free, and the weakest proof there is. The honest next move isn't to trust it — it's to try to break it: does the edge hold across nearby settings and time, or was it luck? Most strategies that look good here don't survive that, and most should stop there. The few that do still haven't met a future nobody has lived yet. Forward-test Bollinger Band Reversion on Tech Sector ETF (XLK) on paper — zero hindsight, losses and all — and get a mechanical alert the day it signals (you trade on your own broker). A hindsight-free track record can only be built by time passing, so the only way to have proof in three months is to start today.
Or stop here — a backtest you can kill for free has already done its job.
Run it yourself
Change the parameters and the window, then re-run — no account needed.
A live badge that re-runs itself and links back here. Free to embed on any blog, newsletter or forum — it shows the honest result, beat or lagged.
<iframe src="https://stratsemble.com/embed/tech-sector-etf-bollinger-reversion-backtest" width="360" height="252" style="border:0;border-radius:12px;max-width:100%" loading="lazy" title="Does the Bollinger Band Reversion strategy beat buy & hold on Tech Sector ETF (XLK)?"></iframe>- • The strategy line is Bollinger Band Reversion on Tech Sector ETF (XLK); the dashed line is simply buying and holding XLK. Beating the dashed line is the whole point — many strategies don't.
- • Max drawdown is the worst peak-to-trough fall you'd have sat through. A higher return with a much deeper drawdown is not obviously better.
- • Every fill assumes next-open execution with costs & slippage on — no acting on prices you couldn't have known.
- • A small number of trades means a small sample. Treat a great-looking result on a handful of trades with suspicion.
This is a hypothetical backtest of a well-known mechanism on past data. It is not advice, not a prediction, and not a claim that the strategy works. I hold no funds and place no orders. The value here is the ability to test an idea honestly — see where it would have helped, and where it would have hurt — before you ever risk real money on your own broker.
How this is computed → · who's behind it · where a backtest fits