10 Best Mid Cap Stocks to Buy According to Billionaires

7. Indivior PLC (NASDAQ:INDV)

Number of Billionaire Holdings: 8

Indivior PLC (NASDAQ:INDV) is a pharmaceutical company focused on opioid addiction treatment, particularly through its flagship product SUBLOCADE, a monthly buprenorphine injection. The company has demonstrated strong growth and resilience, recently reaching a 52-week stock high.

In 2025, Indivior PLC (NASDAQ:INDV) underwent a strategic leadership overhaul to strengthen its market position in the U.S., the primary arena for its operations. Joe Ciaffoni took over as CEO, bringing a fresh vision to the company, while Patrick Barry joined as Chief Commercial Officer to drive commercial expansion, especially around SUBLOCADE. Tony Kingsley also joined the board to enhance governance. These changes reflect a focused effort to boost performance and align leadership with U.S. market priorities. In line with this strategy, the business announced its plan to shift its primary listing from the London Stock Exchange to Nasdaq, aiming for greater visibility and investor engagement in the American market.

On the clinical front, Indivior PLC (NASDAQ:INDV) presented new findings at the 2025 CPDD meeting showing that higher buprenorphine exposure may improve treatment outcomes in patients with high fentanyl use, a critical step given the ongoing fentanyl crisis. The FDA also approved updated labeling for SUBLOCADE, further expanding its clinical utility.