I have seen that two P123 models has a typo in the sell rules.
Built for Stability uses:
eval(Weight > 5, .33, 0) and NoBars > 60
"Low Risk, Rising Dividends Canada" and Low "Risk, Rising Dividends Europe" similar rules.
These rules will give output 1 when true and everyhing will be sold, not scaled. This rule should work as intended -
eval(Weight > 5 and NoBars > 60, .33, 0)
@AlgoMan . I think you are probably correct in that the intention of the designer was to trim the position. However, the rule as written sells when the position gains approx. 50%, as initial weight will be 1.33% .
I have actually found that using gainpct > n as a sell rule can be valuable in some models with a larger number of positions, especially if you use slightly restrictive buy rules. After bullish market conditions you take some profits. It doesn't improve returns materially but it can smooth the equity curve and give a higher sharpe. The nobars rule is unhelpful.