There are also those companies that have a dividend re-investment plan(DRP), whose shares are manipulated down in price during the period just prior to the ex-date, for the purpose of getting more shares in the DRP.
When I held shares in CBA this was as regular as clockwork. Don't know if it still happens, but I sure didn't mind. ;)
So you might want to take that into consideration if you also participate in a DRP. Not long after the ex-date, the share price usually rise back to where it was.
