Ken Fisher is an American billionaire investment analyst, author, and the founder and chairman of Fisher Investments, a fee-only financial adviser. Fisher's Forbes 'Portfolio Strategy' column ran from 1984 to 2017, making him the longest continuously-running columnist in the magazine's history. Fisher has authored eleven books on investing, and research papers in the field of behavioral finance. He is on the Forbes 400 list of richest Americans and as of 2020 is worth $4.3 billion. In 2010, he was named to Investment Advisor magazine's '30 for 30' list of the 30 most influential people in the investment advisory business over the last 30 years. As of September 2020, Fisher's firm managed $135 billion.