Houston's Laura and John Arnold near top of Philanthropy 50

Houston billionaires Laura and John Arnold were among the most generous philanthropists across the country in 2022, according to the Chronicle of Philanthropy's annual report of the top 50 donors.

Driving the news: The Arnolds donated $617 million to Arnold Ventures, their foundation turned limited liability company.

• It landed them sixth on the list, beaten only by Jacklyn and Miguel Bezos, Warren Buffett, Michael Bloomberg, Elon Musk (the only fellow Texan in the top 30) and Bill Gates.
• Rockets owner Tilman Fertitta ranked 37th in part for donating $50 million to the University of Houston.
• Nancy and Rich Kinder were 38th, having donated millions to their own foundation, like the Arnolds.

The big picture: The Arnolds' philanthropic efforts focus on criminal justice, education, public finance and health care issues.

• Laura, a former corporate attorney, and John, a former hedge fund manager, signed The Giving Pledge alongside some of the world's wealthiest people as a commitment to give away the majority of their riches.

What's next: The Arnolds recently spoke out against the pharmaceutical industry, saying it has a "monopoly" on drugs, delivery and pricing.

• "This isn't capitalism," Laura Arnold told NBC News. "This is a form of oppression."