The Envelope indicator is a technical analysis tool that plots two percentage-based bands above and below a moving average, creating a price channel that shows potential overbought and oversold zones. It's one of the simplest ways to spot mean reversion opportunities without diving into complex math.
I remember the first time I put this on AAPL on the daily chart — the 2.5% band caught a pullback in March 2025 that a plain moving average would never have signaled. That's when the Envelope clicked for me.
Here's how it works: take any moving average (SMA, EMA, whatever you prefer), add a fixed percentage above and below, and you get three lines — center, upper band, lower band. If AAPL is at $200 and the 20-day SMA is $190, a 5% envelope puts the upper band at $199.50 and the lower band at $180.50. Price touches the upper band, and you know it's stretched relative to its recent average.
What sets the Envelope apart from Bollinger Bands? Bollinger Bands use standard deviation, so the channel widens and narrows with volatility. Envelope bands stay a fixed percentage away from the moving average at all times. I've found this predictability makes it easier to set consistent entry and exit rules — you're not chasing a moving target.