Fixed fraction versus ATR-scaled sizing

Two workable rules for position size — when each fits a technical trader’s week.

Cloud Transf does not crown a single sizing formula. We teach two that survive contact with live charts.

Fixed fraction

You risk a constant percentage of equity per idea. Size = (equity × fraction) ÷ (entry − stop). It is transparent and easy to journal. It ignores whether this week’s ranges are quiet or violent — the stop distance already embeds that if you place stops from structure.

ATR-scaled fraction

Some desks scale the fraction itself when fourteen-day ATR sits above a look-back average, or they set stop width as a multiple of ATR when structure is ambiguous. Size still comes from pounds at risk divided by pounds per unit; only the stop recipe changes.

Choosing for UK session work

Equity swing traders with clear weekly swings often prefer fixed fraction plus structural stops. Intraday FX traders who face session-driven range shifts may prefer ATR as a stop input, still capped by a hard pound limit per day.

Neither rule replaces a weekly loss cap. Fraction math on single trades will not save a book that keeps firing after three losers.