First thing, you are *not* a investor. The ethereum devs are clearly labelling all of you as "purchasers" of ethereum and not as "investors". Which should be interpreted accordingly.

Second, there is no max cap on this "IPO" and there is no max cap on the produced ether after IPO which means your "purchase" will inflate over time. Just like fiat dollars. Inflation = it will lose value over time.

this picture from a earlier post in this thread shows it all: https://bitcointalk.org/index.php?topic=428589.msg7994191#msg7994191

This picture in that thread clearly shows that the amount of purchased ether will be severely "watered out" over time. Unless the market grows faster and more than the speed of this obvious inflation of ether, the value will drop over time.

Thus, they are labelling you all "purchasers" and not "investors". Most likely they did so in order to make it more "lawyer-proof" if any of the "purchasers" gets pissed for losing money.