Maybe they have been slowly accumulating stock?

No one knows for sure where all the stock flows, we do know that insiders have not made any purchases, or sales recently, but beyond that your guess is as good as mine. Individuals and corporations can own up to 10% without disclosing ownership, so there could be many associated business that have accumulated up to 30M shares each.

I know the volume has been weak and it would have to be a very quiet uplift of shares, but it has been quiet so long I think it would be possible to accumulate a good number without raising eyebrows.

It's also possible that none of that is occuring and no one cares about POET, yet.