Depends on the funds under management, but I would say several...

Depends on the funds under management, but I would say several million shares at least for most as typically it's only the smaller funds fishing these waters. If we have a big fish like Regal (who can still invest in very small stocks like this) decide they like what they see though, they'd need tens of millions of shares to have meaningful exposure.

Most active managers (especially in small caps) don't buy stocks simply to diversify, if they're going to invest its because they've done a large amount of research and have a strong conviction, so they require that the position will be large enough to actually have an impact on their performance.