A Mainer has made it to the Forbes’ list of billionaires, propelled by a family shoe business that swelled in value when it became part of Warren Buffet’s portfolio and saw a massive run-up in stock valuations over the past three decades.

Susan Alfond Photo by Avery Yale Kamila

Susan Alfond of Scarborough and her brothers, Ted and Bill, who live in Massachusetts, are together ranked No. 388 on the latest Forbes list of richest Americans. They each have a net worth of $3.3 billion.

The siblings are No. 1,053, globally, according to Forbes.

Susan Alfond is the only Mainer on the list.

The Alfond siblings were the beneficiaries of the Dexter Shoe Co., established in Dexter by their father, Harold Alfond. He bought a mill in Maine in 1958 and turned it into a shoemaker that sold millions of boots and casual shoes, according to Forbes. In 1993 he sold the company to Warren Buffett’s Berkshire Hathaway for $420 million in stock; the shares are now worth billions of dollars.

Forbes ranked Buffett, with a net worth of $150 billion, as the No. 5 richest person in the U.S. Share values were as of Friday.

The S&P 500 index, a broad measure of stock performance among 500 publicly traded companies, closed Thursday at 5,705.45. It’s up 12-fold from 461.79 in October 1993.

Harold Alfond, who donated tens of millions of dollars to colleges, health centers and other nonprofit organizations, died in 2007 at the age of 93. His youngest son, Peter, died in 2017 at 65.

The Alfonds amassed their wealth through Dexter Shoe Co., which sold to Warren Buffett. David Leaming/Morning Sentinel, file

Buffett regretted buying the Dexter shoe company that halted production in 2001 as the footwear market was swamped by inexpensive imports. In a letter to shareholders in 2008, he said the purchase was the “worst deal that I’ve made.”

“What I had assessed as durable competitive advantage vanished within a few years,” he said. “But that’s just the beginning.”

He said he “compounded this error hugely” by using Berkshire stock to buy Dexter. “That move made the cost to Berkshire shareholders not $400 million, but rather $3.5 billion. In essence, I gave away 1.6% of a wonderful business – one now valued at $220 billion – to buy a worthless business.”

Elon Musk, the founder of electric vehicle manufacturer Tesla and owner of social media platform X, was No. 1 on the Forbes billionaires’ list, with a net worth of $265.2 billion. Jeff Bezos, the founder of Amazon, was second, with a net worth of $215.9 billion.

Editor’s Note: This story has been updated to reflect that Harold Alfond died in 2007.