Speaking to Stella magazine in 2014, Diaz said that her parents instilled thriftiness in her from a young age and so as a result, as an adult, she only spends money on what matters.
"I come from a frugal upbringing so I'm not just going to throw my money away," she said.
"I love to be close to my family and friends, so I spend money on plane tickets, having feasts, buying a ton of groceries and cooking, or going out for an amazing meal, knowing I don't worry about how much the bill costs," she said.
However, Diaz has invested in property and has owned a number of impressive properties in New York and Los Angeles.
According to Capitalism, in 2001, she bought a home above the Sunset Strip in Los Angeles for $1.34 million. While she still owns it today, it's reported that her primary residence is a much larger Beverly Hills compound that she bought from Candice Bergen in 2010 for $9.5 million.
According to the outlet, Diaz also owns a $9.5 million three-bedroom condo in lower Manhattan's Chelsea district and a $12.67 million three-story villa in Montecito that she and her husband Benji Madden purchased in 2022.
Architectural Digest reported in October 2020 that Diaz and the Good Charlotte rocker bought another home in Beverly Hills, a $14.7 million-dollar seven-bedroom farmhouse mansion.