Like the ultra-wealthy who have come before them, they’ll have to figure out what to do with their newfound riches. One of the world’s wealthiest people, Melinda French Gates, has some advice for them.

“Commit now to giving at least half of it away,” she told Fortune when asked what advice she has for this new cohort of IPO millionaires and billionaires. “No matter what it turns out to be, no matter how large, how small it turns out to be. If you even have the ability to invest in these IPOs, believe me, you have the ability to give half away.”

In 2010, French Gates cofounded the Giving Pledge, the promise the ultra-wealthy can make to give away their money in their lifetimes or their wills. She pledged to distribute the majority of her resources within her lifetime. For years, that was mainly through the Gates Foundation, which she cofounded with ex-husband Bill Gates and where she tackled causes across global health. Today, French Gates has her own firm, Pivotal, where she gives to causes including women’s health, women’s political power, caregiving, and more. She recently announced a $215 million philanthropic commitment to women’s health, including women’s midlife health and menopause. Her current net worth is estimated at $19 billion, per Bloomberg, placing her at No. 137 on their billionaires ranking.

More than 250 philanthropists have signed the Giving Pledge, including fellow Pledge cofounder Warren Buffett; Canva cofounders Melanie Perkins and Cliff Obrecht; MacKenzie Scott; Airbnb cofounder Brian Chesky; and Spanx founder Sara Blakely. French Gates says she admires philanthropists like Scott, who has set records with her giving to historically Black colleges and universities, and Alice Walton of Walmart’s Walton family, who is building a new kind of medical school.

French Gates reminds us that “anyone who is a billionaire in the U.S. benefitted from growing up” in this country or coming here as an immigrant. Good roads, access to education and, for the most part, health care make it possible for people to build successful businesses in this country.

And for any billionaires, old or new? “I’ve never thought it’s good for billionaires to be flashy about their wealth, like we’ve seen that over time at all levels of wealth,” she says. “You see it with people who have a million dollars, you see it with people who have $100,000. Flashing that around, that doesn’t do anybody any good. Fine, buy some nice things for yourself, but you don’t have to be flashy about it.”

Read her full interview with Fortune here.