From Stanley Druckenmiller to Ray Dalio, there's a growing...

• From Stanley Druckenmiller to Ray Dalio, there's a growing chorus on Wall Streetthat thinks the stock market is about to embark on a "lost decade," in which returns are virtually flat, similar to the mid-2000s or the 1970s.

  Their concerns are valid when you consider the multi-decade highs in inflation, elevated geopolitical tensions with Russia, and surging volatility in global currency markets.

  But Wharton professor Jeremy Siegel believes those views are unfounded, as he still expects healthy returns going forward for the stock market, according to an interview with CNBC on Friday.

  "I disagree with that completely that the Dow or S&P 500 would be flat [over the next decade]," Siegel said, arguing that there is great value in current stock market prices.

  "When you're talking about 16x earnings, and even if they're clipped by a recession, I think there are absolutely excellent values," Siegel said, though he admitted that in the short-term, "anything can happen... Could it go down more? Of course, in the short run. In bear markets it has gone down more."

  In the short-term, investor concerns are increasingly focused on what the Federal Reserve does with interest rates as they continue to aim for lower inflation. Siegel thinks the Fed would be better served by looking at current market data rather than lagging economic indicators.

  "The Fed has to be forward looking. They have to look at what's going on in the market, in the housing market, in the rental market, in the commodities market," Siegel said, referencing the drop in prices in recent weeks and months.

  But all of this uncertainty ultimately represents a great opportunity for long-term investors, given the value Siegel currently sees in stock prices.

  
  
  Wall Street's growing chorus of a lost decade for stocks is unfounded, according to Wharton professor Jeremy Siegel.

• Siegel believes the stock market could deliver annualized returns of 6% net of inflation going forward.

• "If you're a long-term investor I would absolutely buy now. I think these are absolutely great long-term values," Siegel said.