Why a Fund Made a $143 Million Bet on Indivior With Shares Up a Staggering 200%

On May 15, 2026, Madison Avenue Partners disclosed a new position in Indivior (NASDAQ:INDV), acquiring 4,315,162 shares in the first quarter—an estimated $142.51 million trade based on quarterly average pricing.

What happened

According to its SEC filing dated May 15, 2026, Madison Avenue Partners opened a new position in Indivior (NASDAQ:INDV) during the first quarter by acquiring 4,315,162 shares. The estimated value of the trade was $142.51 million, calculated using the mean unadjusted closing price over the quarter. At quarter’s end, the stake was valued at $131.53 million, reflecting both trading activity and price movements.

What else to know

• This was a new position for the fund, representing 5.72% of reportable U.S. equity assets under management as of March 31, 2026.
• Top holdings after the filing:
  • NASDAQ: SNDK: $393.28 million (17.1% of AUM)
  • NYSE: GHC: $259.91 million (11.3% of AUM)
  • NYSE: CPNG: $176.79 million (7.7% of AUM)
  • NYSE: MICC: $171.11 million (7.4% of AUM)
  • NYSE: MKL: $168.23 million (7.3% of AUM)
• As of Friday, Indivior shares were priced at $36.02, up close to 200% this past year and well outperforming the S&P 500, which is instead up about 28%.

Company overview

Company snapshot

• INDV develops and markets buprenorphine-based prescription drugs, including Suboxone Film, Suboxone Tablet, and Subutex Tablet, primarily for the treatment of opioid dependence.
• The firm operates a specialty pharmaceuticals business model, generating revenue through the manufacture and sale of branded therapeutics across the United States, the United Kingdom, and international markets.
• It serves healthcare providers, addiction treatment centers, and patients affected by opioid use disorder.

Indivior is a specialty pharmaceutical company focused on addressing opioid dependence through proprietary buprenorphine-based therapies. The company leverages its expertise in addiction treatment and operates in the United States, Rest of World, and United Kingdom markets.

What this transaction means for investors

Even with shares nearly tripling over the past year, Madison Avenue Partners appears to believe the market is still underestimating the durability of Indivior's opioid treatment franchise.

The biggest driver remains SUBLOCADE, the company's long-acting treatment for opioid use disorder. First-quarter SUBLOCADE revenue jumped 32% year over year to $232 million, helping push total revenue up 19% to $317 million. More importantly, profitability expanded even faster. Adjusted EBITDA more than doubled to a record $164 million, and GAAP net income climbed to $89 million from $47 million a year earlier.

Management's confidence, meanwhile, showed up in its actions. The company raised full-year guidance, expects SUBLOCADE revenue of up to $990 million in 2026, repurchased $125 million of stock during the quarter, and still has $275 million remaining under its buyback authorization.

Going forward, the key question is whether SUBLOCADE can continue taking share in a large and underserved opioid treatment market, and the risk, of course, is concentration, given that much of the investment case increasingly rests on one product continuing to deliver.

Jonathan Ponciano has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Markel Group. The Motley Fool recommends Coupang and Magnum Ice Cream. The Motley Fool has a disclosure policy.