[H8crilA]

The same happens in the stock market, increased demand (roaring stock market) eventually produces new equity (IPOs). But it doesn't necessarily mean that the new equity is of identical quality (ex: 2000 boom IPOs like Pets.com, or Uber - though we still don't know if Uber is a good stock or not; check back in 5-10 years).

And in the credit market - after all the good debtors are served, and there's still demand for new credit - bad debtors start being served. This keeps on going till it bursts (like in the housing bubble).