What Is Mean Reversion in Practice?
Prices oscillate around means—moving averages, VWAP, range midpoints—especially in balanced markets. Mean reversion traders sell stretched rallies and buy depressed dips expecting return toward center. Tools include Bollinger band pierces, RSI extremes, distance from VWAP in percent, and prior session range edges. Edge exists when volatility is stationary and trend is weak—ADX low, overlapping candles, index range-bound. Mean reversion is the opposite playbook from momentum; using both without regime filter guarantees conflict.
Define the mean you revert to—session VWAP for day trades, twenty-day average for swings.
How Do You Identify Mean Reversion Conditions?
Index chops in defined range for multiple sessions. Stock respects horizontal support and resistance repeatedly. ADX below twenty to twenty-five on entry timeframe. Bollinger band width stable or contracting without directional walk. Avoid mean reversion when stock gaps on news and holds one side of range all day—that is trend day behavior. Pre-market plan marks range high and low; fade only near edges, not mid-range random entries. Sector neutral or weak correlation supports pair-style mean reversion less relevant for single-stock retail.
First hour establishes range on many days—fading before range is defined is premature.
What Entry and Exit Rules Apply?
Short at upper range or plus-two Bollinger pierce with rejection candle; stop above extreme plus buffer. Long at lower range or minus-two pierce with stop below low. Target range midpoint, VWAP, or opposing band—not always full reversal to other extreme. Scale partial at mean; trail remainder lightly. Require confirmation—close back inside band or failed break of level. One-sided persistence: three pushes into band without rejection can signal breakout brewing—stand down.
Reward-to-risk must justify fade—tight stop at extreme with target at mid-range often yields favorable math.
When Does Mean Reversion Fail Catastrophically?
Strong trend days when bands walk and RSI stays overbought. Breakout from multi-week range on volume—fade becomes fighting trend. Macro shock gaps that reprice entire sector. Shorting meme-stock extensions without borrow and halt awareness. Averaging into losing mean reversion doubles death when trend accelerates. Circuit breaker: exit after one full stop; do not double size at same level hoping for snapback. Regime detection is survival skill for mean reversion traders.
When VWAP slope is steep all session, mean reversion shorts above VWAP are low-probability.
How Should You Size Mean Reversion Trades?
Smaller size than trend trades—win rate may be higher but occasional trend days produce large losses. Risk half normal percent per trade or use hard daily loss cap. Stops must be tight beyond extension extreme; if stop width exceeds planned R, skip. Track rolling win rate; deterioration often means market shifted trending. Mean reversion suits patient traders who accept many small wins and rare large losses if unfiltered. Combine with time-of-day—midday ranges favor fades; open trend windows do not.
Journal regime tag on each fade—data proves whether you traded reversion in trend conditions.