Nvidia is a stock bubble and its popping could trigger a broader market crash, investing legend Rob Arnott says

• Nvidia stock has formed a bubble and should it pop, that could trigger a total market crash, investing legend Rob Arnott said. 
• He classed the chipmaker company as a "textbook story of a Big Market Delusion" due to its sky-high valuation. 
• "Would Nvidia's popping bring down the whole market? "It's very possible," Arnott said. 

Nvidia's stocks have formed an asset bubble following this year's stunning rally - and should it pop, that could trigger a broader market crash, according to investing legend Rob Arnott.