Prokhorov bought the team then known as the New Jersey Nets for less than $400 million in 2009 and sold it in 2019 for $2.35 billion. No. [4] She was the richest person in Massachusetts in 2020. For doing just that, Abigail Johnson, Chairman & CEO of Fidelity Investments, ranks no. The Ferrero fortune dates back to 1940s Italy, when Michele Ferrero created what is now known as Nutella. He also has stakes in Renaissance Capital and Renaissance Credit, both banks. Details about Northern Necks holdings were disclosed in the 2010 FMR prospectus due to accounting principles that required disclosure because of the Johnson familys control of FMR. Combined, the richest Americans hold $3.2 trillion; this is an increase of $240 billion from last year. According to an SEC official who asked not to be identified because the agency isnt authorized to discuss specific companies, if any person had 25 percent or more ownership of FMR, it would have to be specifically disclosed. The Johnsons hold some personal investments through Boston- based Northern Neck Investors LLC, an investment adviser that has $2.2 billion in assets. Combined with the familys collection of other assets, including a lumberyard chain, a farm and interests in oil and gas, the Johnson clan is worth $22 billion, according to the Bloomberg Billionaires Index. She is now the fourth-richest woman in the world after L'Oreal heiress Francoise Bettencourt Meyers, MacKenzie (Bezos) Scott, and Walmart heiress Alice Walton. For the purposes of this list, families whose wealth stems from a joint company or enterprise are being considered as a single entry. A.N. Source of wealth:Self-made; Renaissance Technologies. It's still owned by the Albrecht family trust. The next wealthiest Bay Stater Valentin Gapontsev, 81, founded IPG Photonics, the creator of high-power fiber-optic lasers, according to Forbes. Returning to the list this year after dropping off in 2017, with an estimated $3.2 billion net worth, is Gail Miller, largely thanks to selling most of her familys majority stake in NBAs Utah Jazz for some $1.66 billion in October 2020. Now the world's largest private equity firm, Blackstone manages $439 billion in assets.