Wharton professor Jeremy Siegel
Wharton professor Jeremy Siegel is a long-time market commentator.
  • Wharton professor Jeremy Siegel rejects the notion that US stocks are overvalued, saying they are in fact "underpriced".
  • Billionaire investors Jeremy Grantham, Bill Gross and Jeffrey Gundlach have recently said equities look overpriced.
  • "Even if there is a mild recession, these are great long-term values," Siegel said, referring to the current levels in stocks.

A growing chorus of Wall Street experts have recently warned US stocks look too expensive, and are due for a correction.