When filtering the more than 2,200 stocks on the ASX in the hunt for that under-appreciated gem, it is essential to have an efficient and effective system to sort the wheat from the chaff. So, following on from our recent report on how professional investors generate new investment ideas, we asked our five contributors: ‘once identified, how do you filter these ideas down to determine the best opportunities?’ The responses reveal to Livewire readers the processes honed by decades of experience of some of the best performing small-cap and midcap managers in the Australian market. Insights provided by OC Funds Management, K2 Asset Management, Katana Asset Management, Bennelong and Totus Capital.