Global stock markets have been buoyed by 'stupid' people ignoring China and Russia risks, veteran investor says

• Stocks have rallied this year despite economic risks because "people are stupid" and too complacent, David Roche said. 
• The veteran investor highlighted key economic threats to global equities including high interest rates and China's slowdown. 
• "I think the downside in markets is very big, still, at these levels and they're not priced for it," he said. 

Global stock markets have had a strong year-to-date run in spite of economic uncertainties "because people are stupid" and too complacent, veteran investor David Roche said.