The 25 richest self-made billionaires

Net worth: $23.5 billion

Age: 75

Country: Mexico

Industry: Telecom

Source of wealth: Self-made; Grupo Carso

The richest man in Mexico owns more than 200 companies in his home country through a conglomerate called Grupo Carso — also known as Slimlandia. The son of Lebanese-Mexican entrepreneurs, Carlos Slim Helú gained control of his father’s retail and real-estate businesses upon his death. After earning a civil-engineering degree, Slim built a diversified portfolio throughout the 1960s, ’70s, and ’80s that now dominates the Mexican economy.

A savvy investor with a knack for well-timed deals, in 1990 Slim took Grupo Carso public, and shortly thereafter he capitalized on Mexico’s decision to privatize its telecom industry. Grupo Carso acquired state phone company Telmex, which now owns 80% of the telephone lines in Mexico. In 2008, Slim Helú bought a 6.4% stake in The New York Times for $127 million after the stock had cratered, making him the largest shareholder. He has since increased his ownership to 17%, a stake worth $340 million thanks to The Times’ resurgence.

Slim still has aspirations to grow his empire — which includes interests in the financial, industrial, telecommunications, and media sectors — especially in his home country, where he invested $4 billion in 2015. He has already begun distributing billions of his fortune to his family as part of his estate planning, otherwise his net worth would be significantly higher.