This is good advice. Peter Lynch puts it best (and actually, he was misquoted about the mall story 25+years ago): https://www.wsj.com/articles/peter-lynch-25-ye

This is good advice. Peter Lynch puts it best (and actually, he was misquoted about the mall story 25+years ago): https://www.wsj.com/articles/peter-lynch-25-years-later-its-not-just-invest-in-what-you-know-1449459844 https://www.wsj.com/articles/peter-lynch-25-years-later-its-... tl;dr you better really know what you're investing in. If you don't know, don't invest even if you miss out on the next "big thing".