SpaceX President Gwynne Shotwell said Monday she and her husband will donate a portion of their SpaceX stock to seed roughly 2 million Trump Accounts, becoming the second billionaire couple to underwrite the tax-deferred children's investment program that began delivering federal deposits over the July 4 weekend.

The pledge, disclosed in a post on X, ranks as the biggest private commitment since Michael and Susan Dell put up $6.25 billion in December and follows employer-match announcements from Goldman Sachs, Morgan Stanley, Intel, Robinhood and Micron. Shotwell said the gift would place a "bit more emphasis" on children who live near her family's home in central Texas.

"We have been fortunate in our careers and hope this gift encourages the next generation to continue the journey of enabling humanity to live and fly amongst the stars," Shotwell wrote.

Shotwell, SpaceX's chief operating officer, holds a stake worth roughly $2.4 billion after last month's record-breaking IPO. President Trump told CNBC's Joe Kernen on Thursday he expected SpaceX Chief Executive Elon Musk to donate company stock as well.

Families begin to invest

The Treasury began delivering $1,000 seed deposits Saturday to babies born between 2025 and 2028. Families had signed up more than 6 million children ahead of the launch, including 1.4 million infants eligible for the federal contribution, according to the department. Parents, grandparents and employers can add up to $5,000 a year; the accounts convert to a traditional IRA at age 18.

Will Matthews, a senior auditor in Columbus, Ohio, opened accounts for his two young children and said a third on the way would qualify for the seed. Each child was likely to receive a $250 charitable contribution from the Dell Foundation, which targets children 10 and under in ZIP codes below a $150,000 median income.

"If it's free money, we'll take it," Matthews said. He does not plan to contribute beyond those grants, prioritizing 529 college-savings plans instead. "These accounts don't have that many crazy tax advantages for me to be gung-ho on putting all my eggs in this basket," he told CNBC.

Adam Bergman, IRA Financial's founder, plans to contribute the $5,000 annual maximum for each of his two sons and eventually convert the accounts to Roth IRAs. "They're going to be tax-free millionaires," he told CNBC. His 15-year-old son, Aven, said the account had reshaped how he viewed markets: "You need to be patient; it's going to go up."

The counterpoint

Sen. Dave McCormick, R-Pa., who cast the deciding Senate vote for the Working Families Tax Cuts Act that created the accounts, argued in a Fox News op-ed Monday that the program answers rising wealth concentration without a new federal agency; the top 1 percent's share of national wealth has climbed from about 27 percent to 32 percent since the global financial crisis, he wrote. Democratic lawmakers had not publicly detailed a coordinated response by press time, though Matthews' reservations echo a recurring critique that the tax structure most rewards families able to contribute the full $5,000.

Brad Gerstner, the Altimeter Capital founder who helped spearhead the program, called Shotwell's donation an "extraordinary gift" and told CNBC: "This is not a program, this is a platform. It is the largest unlock of direct philanthropy in the history of the country."