[kooshball]

you're right that in any funding round (private or public ipo) there is dilution. your ownership in % will go down.

however no company will be able to predict future dilution so this is not really something they can tell you with confidence.

the only thing you can do is gauge current state of the company (funding, readiness for ipo) and try to estimate future dilution but even this is non trivial for early stage companies.