> For the complete documentation index, see [llms.txt](https://docs.bitbrokertrade.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.bitbrokertrade.com/english/untitled/explanation-functionalities/how-is-the-size-of-a-transaction-determined.md).

# How is the size of a transaction determined?

The transactions always cover 18% of the outstanding euro balance on your exchange. The smallest transaction size that we use is € 50. At trader level you can enter the size of the purchase transactions yourself with the setting "Average purchase amount".