So you're suggesting that investors who bought in later are more...

So you're suggesting that investors who bought in later are more likely to trade away a piddly number of shares they receive through the SPP to such a degree that it will cause volatility on the SP? I'm afraid I can't agree with you. To the best of my knowledge a listed company can't provide preferential treatment to a certain cohort of shareholders as part of a SPP. If SP3 were planning to do that I will be writing to the regulator to enquire about the legitimacy of such a proposal. In any case any such proposal should be evident in the prospectus. I can't see it happen.