Surviving 2008 and 2022 with a 10% Drawdown: A 20-Year ETF Mean Reversion Study.

u/vaanam-dev · Reddit — r/algotrading · January 15, 2026 at 17:58 · ⬆ 72 pts · 💬 30 comments  | View on Reddit ↗
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Original Reddit post

A 20-year ETF mean-reversion backtest finds that buying SPY, QQQ, DIA, or IWM below the lower Bollinger Band while above the 200-day SMA and exiting at the upper band produced 10.03% CAGR with 10.74% max drawdown.

QQQ — LONG The author includes QQQ in a multi-ETF mean-reversion basket, applying the same rule: buy when it closes below the lower Bollinger Band and above the 200-day SMA, then exit at the upper band. QQQ is second in priority and is bought only if SPY does not first meet the entry criteria. The combined backtest from Jan 2006 to Dec 2025 is claimed to produce 10.03% CAGR with 10.74% max drawdown and 5.50 profit factor. The main stated risk is drawdown and trade costs.

I want to test this on multiple ETFs, so I picked - SPY, QQQ, DIA, IWM and run the strategy at the same time. What ever etf falls into my entry criteria will be bought, if SPY and QQQ both comes into the radar only SPY will be bought because that is first in our list of ETF.

Unpriced research observations (excluded from Calls and Returns):

SPY — LONG The author claims that buying SPY when it closes below its lower Bollinger Band and above its 200-day SMA, then exiting when it closes above the upper Bollinger Band, produced 7.22% CAGR with 15.24% max drawdown over Jan 2006-Dec 2025. The proposed mechanism is mean reversion after oversold dips within an uptrend, letting winners run to the upper band rather than the middle band. The main stated risk is catching falling knives during crashes, addressed by the 200-day SMA filter, and the backtest includes $8,593.75 in fees/slippage. resolved_entity_name_mismatch

Entry -

  • Buy the SPY when it closes below it's lower line of Bollinger bands AND
  • SPY's close > it's SMA 200

Enhanced Exit -

  • Exit the SPY when it closes above it's upper band.

SPY — LONG The author extends the mean-reversion strategy to a basket of SPY, QQQ, DIA, and IWM, buying whichever ETF first meets the entry criteria and exiting at the upper Bollinger Band. The combined backtest from Jan 2006 to Dec 2025 is claimed to produce 10.03% CAGR with 10.74% max drawdown, 5.50 profit factor, and $15,780.62 total costs. SPY has first priority, so it is bought if it qualifies even when QQQ also signals. The stated mechanism is diversified dip-buying in bull markets, with the main stated risk being drawdown. resolved_entity_name_mismatch

I want to test this on multiple ETFs, so I picked - SPY, QQQ, DIA, IWM and run the strategy at the same time. What ever etf falls into my entry criteria will be bought, if SPY and QQQ both comes into the radar only SPY will be bought because that is first in our list of ETF.

DIA — LONG The author includes DIA in a multi-ETF mean-reversion basket, buying when it closes below the lower Bollinger Band and above the 200-day SMA, then exiting at the upper band. DIA is third in priority after SPY and QQQ, so it is bought only if neither higher-priority ETF qualifies. The combined backtest from Jan 2006 to Dec 2025 is claimed to produce 10.03% CAGR with 10.74% max drawdown and 5.50 profit factor. The main stated risk is drawdown and trade costs. resolved_entity_name_mismatch

I want to test this on multiple ETFs, so I picked - SPY, QQQ, DIA, IWM and run the strategy at the same time. What ever etf falls into my entry criteria will be bought, if SPY and QQQ both comes into the radar only SPY will be bought because that is first in our list of ETF.

IWM — LONG The author includes IWM in a multi-ETF mean-reversion basket, buying when it closes below the lower Bollinger Band and above the 200-day SMA, then exiting at the upper band. IWM is fourth in priority after SPY, QQQ, and DIA, so it is bought only if none of the higher-priority ETFs qualify. The combined backtest from Jan 2006 to Dec 2025 is claimed to produce 10.03% CAGR with 10.74% max drawdown and 5.50 profit factor. The main stated risk is drawdown and trade costs. resolved_entity_name_mismatch

I want to test this on multiple ETFs, so I picked - SPY, QQQ, DIA, IWM and run the strategy at the same time. What ever etf falls into my entry criteria will be bought, if SPY and QQQ both comes into the radar only SPY will be bought because that is first in our list of ETF.

Score 72
Comments 30
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u/vaanam-dev Reddit r/algotrading
Long QQQ in multi-ETF mean-reversion basket
The author includes QQQ in a multi-ETF mean-reversion basket, applying the same rule: buy when it closes below the lower Bollinger Band and above the 200-day SMA, then exit at the upper band. QQQ is second in priority and is bought only if SPY does not first meet the entry criteria. The combined backtest from Jan 2006 to Dec 2025 is claimed to produce 10.03% CAGR with 10.74% max drawdown and 5.50 profit factor. The main stated risk is drawdown and trade costs.
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This Reddit post, published January 15, 2026, features u/vaanam-dev discussing QQQ. 1 trade idea extracted by AI with direction and confidence scoring.

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