> Why one need underwriter at all? Why certain investors are offered lower unfair price? Those are two completely different things. Underwriters are there to

> Why one need underwriter at all? Why certain investors are offered lower unfair price? Those are two completely different things. Underwriters are there to ensure that the company is able to predict the amount of money that an IPO will raise. There are all sorts of legitimate reasons that a company needs to be able to predict the amount of money an IPO will bring in, starting with the fact that it's literally the entire point of an IPO. Even in the Dutch-auction style that's been proposed in other comments, you don't solve the problem that some investors will be able to invest at the IPO price and others won't. The supply is finite; as long as demand ends up exceeding supply, you're still running the risk of people not being able to purchase shares, except now you've also done away with the invariant that a company can predict the amount of money it's going to raise. (Note that even Google, which famously used a Dutch auction for its IPO, had an underwriter, and the underwriter had to change the share price at the last-minute because some larger institutional investors indicated that they were going to back out of the IPO and wait to trade later in the day. If that had ended up happening, it would have completely wiped out the money that Google was trying to raise by having the IPO in the first place).