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

The fund's $142.5 million bet on Indivior underscores confidence in the company’s opioid-treatment franchise as the stock has surged about 200% year over year. Madison Avenue Partners disclosed in a May 15, 2026 SEC filing that it opened a new position by buying 4,315,162 Indivior shares, valued at roughly $142.51 million using the quarter’s average price. At quarter end, the stake was worth about $131.53 million, reflecting both trading activity and price moves. The stake represented 5.72% of the fund’s reportable U.S. equity assets as of March 31, 2026. Indivior traded near $36.02, up roughly 200% over the past year. Indivior’s portfolio centers on buprenorphine-based therapies, including SUBLOCADE, Suboxone Film, and Subutex Tablet. In Q1, SUBLOCADE revenue rose 32% year over year to $232 million, contributing to total revenue of $317 million, up 19%. Adjusted EBITDA more than doubled to a record $164 million, with GAAP net income of $89 million versus $47 million a year earlier. Management raised full-year guidance and expects SUBLOCADE revenue up to $990 million in 2026. The company also repurchased $125 million of stock in the quarter and has $275 million remaining under buyback authorization. Investors will weigh SUBLOCADE’s ongoing market share against concentration risk.