- The US is going through a "textbook" financial crisis, according to billionaire Leon Cooperman.
- That means poor returns for stocks, he added, warning the S&P 500 wouldn't hit a high again for a long time.
- Cooperman has warned markets of an coming recession, and said stocks could plunge 20% this year.
The US is going through a "textbook" financial crisis – and that means investors should expect sluggish returns for in the S&P 500 for a long time, according to billionaire investor Leon Cooperman.