The price of securities in the Primary
Market is determined by

What someone else is willing to pay for it.  

There's an argument that it doesn't even matter if that someone else is able to pay for it; knowledge of a competing bid influences security price because it provides a simple point from which to determine not-enough or too-much.

one of the major compromises in the constitutional convention was between the small states and big states. the small states wanted each state to have the same number of representatives in congress. the big states wanted representation based on population.

determination