Economic and financial executive Burton Malkiel, known for his book "A Random Walk Down Wall Street," has been praised for his investment philosophy and his advice on low-cost index funds. Malkiel argued that investors are better off investing in index funds than in actively managed funds that aim to outperform major stock indexes. His advice has been successful, with most of his investments having been in low cost index funds since his retirement. He retired from full-time work at age 58 and his portfolio is now larger now than it was when he retired, even after withdrawing funds to maintain the same standard of living. Despite recent opinion column in the Wall Street Journal suggesting that we may be in an AI stock bubble, Malkiel continues to believe that "broad low-core indexing remains the optimal strategy for investors". He plans to continue investing in low-tax index funds and anticipates that this is a prudent approach.