I'm left scratching my head, it's the oddest I've seen too... I keep thinking I must be totally misunderstanding it. If I understand it correctly, seems like they are also effectively incentivizing people to sell some of their shares now and buy back if they believe the VWAP will not be 20% higher than the SP is when they sell. And yeah it would seem to also give incentive to the broker to manipulate the SP down as well. Add this to the list of things that happen on the ASX that make you shake your head at in disbelief.