I know but author do poke their nose into investment sometimes there are right and at other times they are wrong. Even the famous Physicist Albert Einstein was not an exemption when he invested in South Sea stocks. Read what Benjamin Graham wrote about the incident:
“And back in the spring of 1720, Sir Isaac Newton owned shares in the South Sea Company, the hottest stock in England. Sensing that the market was getting out of hand, the great physicist muttered that he “could calculate the motions of the heavenly bodies, but not the madness of the people.” Newton dumped his South Sea shares, pocketing a 100% profit totaling £7,000. But just months later, swept up in the wild enthusiasm of the market, Newton jumped back in at a much higher price—and lost £20,000 (or more than $3 million in today’s money). For the rest of his life, he forbade anyone to speak the words “South Sea” in his presence.”
― Benjamin Graham, The Intelligent Investor