Can you lend me twenty?

You don't make money on loans unless you're Donald (``If I'm bankrupt that's the banks' problem, not mine'') Trump.

You make it on Initial Public Offerings.

You need for that, however, income; you capitalize the income (divide by interest rate), and sell shares. Then you go on vacation.

See _Supermoney_ by Adam Smith. Anyway I think that was the book.

Or you find a way to convince investors there will be income someday, sell your IPO, sell off your stock, and move on while the company founders.

The stock market serves two societally useful purposes. One is to provide a way for companies to raise capital to expand their operations, and to enable the investors who provided capital to realize their profits or to recover their investment and move on to something else. The other is to transfer investment money from those too stupid to use it well to those with more brains or understanding of business...