lighning bolt icon An icon in the shape of a lightning bolt. lighning bolt icon An icon in the shape of a lightning bolt. Impact LinkThis story is available exclusively to Business Insider subscribers. Other research has found that TikTok, in particular, is one of the main sources of investing advice for younger people. Related stories Business Insider tells the innovative stories you want to know Business Insider tells the innovative stories you want to knowEach video received an A-F trade for each category, resulting in an overall grade.