The broker now has 105 clients listed on the alternative investment market, up from 101 at the end of last quarter.
It means Finncap has a 20 client lead over its nearest rival in the space, Cenkos Securities, which had 85 clients for the quarter ending September.
Cenkos and Peel Hunt also did well on the FTSE 100 Aim list – a list of biggest junior stock market listed companies – moving up to joint second place from third and fourth respectively with 14 clients each.
Canaccord Genuity tops the list, with 16 clients. Finncap was also top of the list for nominate adviser rankings on Aim, according to the poll, which is compiled by Adviser Rankings.