Is stock market a black market ?

Sensex is soaring at levels all time high and setting new records
everyday. I, too, have made some money through mutual funds, but that
couldn't stop few thoughts coming to my mind.

I don't understand how a company benefits if its stock price in the
market rises. Company gets the money only when it releases the shares
in the market for the first time (IPO). That is the real investment
people make in the company. After that, it is only the people (stock
traders) who make money from the company's stock. Isn't it equivalent to
selling movie tickets in black outside the theater. Theater owner gets
only the legitimate price of the ticket. If the movie is good, people
selling the tickets in black make money by increasing the price of the
ticket.

Then, I don't know how economy gets help from the rising stock market.
If people put money in stock market, the money is not going in
developing the nation or economy (except money invested in IPO), it is
just exchanging hands of the stock traders.