The number of individuals with at least $1 million in their 401(k) retirement accounts has grown by approximately 25% this year. Fidelity, the largest retirement plan and individual retirement-account provider in the U.S., reported that as of June 30, around 378,000 retirement savers in Fidelity plans held balances exceeding $1 million, compared to 299,000 at the end of 2022. Similarly, the number of IRA millionaires increased by a similar percentage to nearly 350,000 by June 30. This increase in account balances corresponds with a surge of 16.71% in the S&P 500 stock index in the current year. In contrast, the previous year saw a 32% decrease in the number of Fidelity 401(k) millionaires due to declines in both stocks and bonds. These million-dollar savers typically have distinguishing features such as high savings rates, averaging 17.2% of their pay, with employers contributing an additional 9.3%. The average age of 401(k) millionaires is 59, and they tend to be diligent savers rather than relying on one-time stock gains.