Nvidia CEO Jensen Huang's investment advice involving the company's suppliers is dangerously rosy, Bloomberg Opinion columnist Shuli Ren says. Ren argues that concrete guidance, not outsized optimism, is what's needed from Huang and other tech titans. -------- More on Bloomberg Television and Markets Like this video? Subscribe and turn on notifications so you don't miss any videos from Bloomberg Markets & Finance: https://tinyurl.com/ysu5b8a9 Visit http://www.bloomberg.com for business news &