AstraZeneca-BMS $600 Billion Mega-Deal Rumor Draws Wall Street’s Ire; $33 Billion in Market Value Wiped Out

Wall Street reacted coldly to reports of a potential mega-merger between pharmaceutical companies AstraZeneca and Bristol Myers Squibb (BMS), wiping out tens of trillions of won in AstraZeneca’s market capitalization.

On the 3rd (local time), the Financial Times (FT), citing multiple sources, reported that the two companies had discussed a merger in recent months. Reuters also reported that the parties had held preliminary discussions about a combination.

The market responded with immediate selling. AstraZeneca shares plunged more than 8% during the day, erasing approximately $22 billion (about 33 trillion won) in market capitalization. BMS shares also fell nearly 1.5%.

If completed, the deal would create a giant pharmaceutical company worth approximately $400 billion (about 600 trillion won). AstraZeneca could significantly strengthen its oncology and cardiovascular treatment businesses, which accounted for 44% and 22%, respectively, of its revenue last year.

BMS owns blockbuster drugs including the immuno-oncology drug Opdivo and the blood thinner Eliquis. However, those products face patent expirations within the next few years, making new growth drivers urgently necessary.

BMS has posted mixed results in new-drug development. Its recent earnings exceeded market expectations on the strength of newer drugs such as Reblozyl and Breyanzi, but Eliquis still made a substantial contribution. Products including the schizophrenia treatment Cobenfy, acquired for $14 billion (about 21 trillion won), have yet to deliver commercial results.

Michael Leuchten, an analyst at Jefferies, described the acquisition rumor as “news that makes you scratch your head.” He pointed out that AstraZeneca is already showing strong growth under CEO Pascal Soriot.

As of the end of 2025, AstraZeneca had 16 blockbuster products generating more than $1 billion in annual revenue, and expects to increase that number to more than 25 by 2030 while surpassing $80 billion (about 120 trillion won) in total revenue. Leuchten added, “If there is a company that does not need financial engineering, it is AstraZeneca.”

Alex Torgerson, an M&A partner at consulting firm West Monroe, said, “The market’s skepticism is understandable,” adding, “It is natural for investors to question why AstraZeneca, which has built one of the industry’s best organic growth stories, would pursue a complex $600 trillion M&A deal.”

Experts also predict that the path to completing the deal will be difficult. Matt Phipps, an analyst at William Blair, said AstraZeneca’s M&A would face intense scrutiny from U.K. antitrust regulators, particularly because the company is a “cornerstone” of the British biotech R&D ecosystem.

Valuing the companies is also considered a challenge. Chung Huynh, an analyst at RBC Capital Markets, said, “With BMS’ key products facing patent-expiration pressure while the company awaits important clinical data readouts for drug candidates such as Cobenfy and the blood thinner milvexian, the two sides may find it difficult to reach agreement on valuation.”

Meanwhile, some analysts say the M&A rumor could signal a shift in the pharmaceutical industry’s deal-making trends. Torgerson said, “Regardless of whether the deal is completed, it is a sign that big pharma companies are beginning to think differently about growth,” adding, “For years, $5 billion-$10 billion ‘bolt-on’ acquisitions were popular, but now transformative ‘mega-deals’ may once again be considered as an M&A strategy.”

AstraZeneca declined to comment on the report, while BMS did not issue a statement.