Australia's richest person, Gina Rinehart, increased her bet on President Donald Trump's social media platform, Truth Social, in the second quarter, while the market value of her U.S. stock portfolio increased by over $600 million.

According to regulatory filings, Rinehart's Hancock Prospecting Ltd. held a portfolio of U.S. stocks and exchange-traded funds (ETFs) worth approximately $3.1 billion as of June 30. Notably, the firm's holdings in Trump Media & Technology Group Corp., the operator of Truth Social, increased by 67% in the second quarter.

Rinehart also owns a 7.8% stake in MP Materials Corp., the little-known U.S. rare earth producer announced in July by the U.S. Department of Defense in an unprecedented $400 million investment.

MP Materials' stock price has since surged 70%, making Rinehart's stake worth over $1 billion. Documents show Rinehart also increased her stake in Teck Resources Ltd.

The entrepreneur, who made her fortune developing a large iron ore mine in Western Australia, is currently worth $27 billion, according to the Bloomberg Billionaires Index. Rinehart, 71, has publicly supported Trump and urged the Australian government to implement similar policies. Her stake in Trump Media & Technology is currently worth approximately $4.5 million.