No it doesn't work that way for a number of reasons. Firstly to...

No it doesn't work that way for a number of reasons. Firstly to do that would be market manipulation and illegal and if you think these funds can't and don't get audited for that think again. Second, different nominees represent different end clients/investors a fund manager can treat them differently or advantage one over the other. Third, you would have seen the substantial holdings move by now.

There are a number of other reasons including blowing out commissions etc. Bottom line some manipulation undoubtedly does occur in thinly traded micro caps but in the rest of the market it is mostly a Hotcopper forum myth. Whoever is shorting BET is collectively (it won't be one fund) short a shed load of stock, there's no way they buy that back and get long at the same time - mathematically it just doesn't make sense.