Mean reversion assumes the move will fade

strategyPublished 20 October 20261 min readmulti asset

Key points

• Fading a move is the opposite bet from following it.
• Costs matter more when the expected move back is small.
• A tail move is the case the range rule did not size for.

What is going on

A range rule buys below a lower line and sells above an upper line, or it trades a spread back toward a historical gap. The profit, if the fade happens, is the distance back toward the line minus the spread and any commission. If the line was estimated from a calm sample, a new level can look like an extreme that never returns. The position then grows or the stop, if you wrote one, is the only exit.

Why it matters

Small targets and frequent trades make the spread a large share of the plan. A rule that looks profitable before costs can be a loss after them. Adding size because the price is ‘more extreme’ increases the loss if the regime has changed. That is not a more confident version of the same idea. It is more exposure to the failure.

What to watch

Write the reference, the entry distance, the exit, and the loss at which the idea is retired. Include the spread you are willing to assume. Do not add to a losing fade unless that add was in the original rule, with a maximum size.

Risks

Prices can trend. A short-volatility shape, which many fades resemble, earns small amounts and occasionally loses a large one. This note does not show a win rate.