Arithmetic, not impression
Extra trades are not neutral: each pays the full spread and slippage, while arriving from weaker conditions because they fall outside what the strategy actually produces.
The result is simple arithmetic: a lower expectancy per trade multiplied by a higher trade count gives a worse return, not a better one. That is the arithmetic behind an observation many traders make — their busiest months are not their most profitable.
Measuring a bias you cannot feel
Behavioural biases are not fixed by general advice, because in the moment they do not feel like biases — they feel like sound decisions. The only practical approach is for each bias to have a measurable signature in your trade record.
So each page here gives the numerical marker that exposes the bias rather than asking you to "be disciplined". You do not need to be told to have discipline; you need to know whether you currently lack it.
A worked example
The reference record: expectancy +0.20R per trade, risking 1% of $1,000 — $2 per trade before costs.
At $3 of cost per trade the net becomes −$1. Now double the trade count: 200 instead of 100 does not double the profit but the loss — −$200 rather than −$100. Yet the trader feels they are working twice as hard.
This is why reducing trade count is sometimes the fastest route to a better result: what multiplies is net expectancy, not activity. See expectancy.
Common mistakes with this term
- Measuring diligence by trade count, when the count multiplies net expectancy whether it is positive or negative.
- Loosening entry conditions on quiet days to find activity, lowering the quality of the whole sample.
- Overlooking that correlated trades on similar instruments are effectively one position at multiplied size.