2025 marked the sharpest rebound in global mergers and acquisitions since the pandemic era, with dealmakers pursuing scale, technology leadership, and strategic repositioning amid a shifting macroeconomic backdrop. Deal value rose 40% from 2024 and approached $5 trillion, second only to 2021, driven by a record wave of megadeals and a renewed appetite from both corporates and private equity sponsors.
Larger transactions dominated the year,with transactions over $10 billion comprising roughly 30% of global deal value — in large part due to lighter antitrust pressure and fewer regulatory headwinds in the United States. Technology (predominantly AI) was the driving force of deal activity, as corporations sought out consolidation to strengthen their AI tech stacks. Looking ahead to 2026, experts anticipate continued megadeal appetite, tempered by regulatory scrutiny and favorable macroeconomic conditions.
Below, we take a look back at the largest and most impactful M&A deals of 2025, and how they are shaping the macroeconomic outlook for 2026.
Related Reading: Major Mergers and Acquisitions of 2024
Union Pacific Corp.’s Acquisition of Norfolk Southern Corp.: $85 billion (Expected to Close in 2027)
This once-in-a-generation transaction will create the first trans-continental US railroad. The deal is structured as a stock-and-cash transaction where Norfolk Southern will become a direct, wholly owned subsidiary of Union Pacific.
The merger is expected to generate $133 million in annual capital synergies by optimizing the two companies’ combined fleet and network. It is also expected to reduce emissions and road congestion by removing over 2 million truckloads from highways. While the transaction is pending approval from the Surface Transportation Board, shareholder approval has already been secured, and the deal is expected to close in early 2027.
Netflix’s Acquisition of Warner Bros.: 82.7 billion (Announced in December 2025)
In December 2025, Netflix and Warner Bros. Discovery entered a definitive agreement for Netflix to acquire Warner Bros., including its film and television studios, HBO, and HBO Max. While the deal was at first slated to be a stock-and-cash transaction, it was amended to be an all-cash transaction in January 2026.
If the deal closes, it will fundamentally reshape the streaming industry, giving Netflix an unprecedented and uncontested power edge over its competitors. The deal is currently still awaiting regulatory approval from the Department of Justice and the European Commission.
Kimberly-Clark’s Acquisition of Kenvue: $48.7 billion (Expected to Close in 2026)
In a landmark deal for the consumer staples industry, Kimberly-Clark (maker of Huggies and Kleenex) entered into a definitive agreement to acquire Kenvue in November 2025. Kenvue is a Johnson & Johnson spinoff that is behind Band-Aids and Tylenol. The deal was a result of a strategic review initiated by Kenvue in July 2025 to address operational underperformance and unlock shareholder value.
This merger would create a $32 billion global health and wellness leader with tremendous market power and a global reach that touches roughly half of the world’s population. The deal has already received SEC clearance and is currently awaiting a pivotal shareholder vote.
Google’s Acquisition of Wiz: $32 billion (Expected to Close in 2026)
In March 2025, Google entered into a definitive agreement to acquire Wiz, a leading cloud security platform. This is Google’s largest acquisition yet, significantly surpassing its $12.5 billion purchase of Motorola in 2012. The acquisition is intended to bolster Google Cloud Platform’s security offerings and enhance its competitiveness against AWS and Microsoft, while also accelerating trends in cloud security and multicloud capabilities in the AI era. Upon completion, Wiz will be integrated into the Google Cloud segment. The deal is still undergoing regulatory review, with an outcome likely by March 2026.
Constellation Energy’s Acquisition of Calpine: $26.9 billion (Announced in 2025; Closed in January 2026)
Announced in January 2025, this deal officially closed a year later. The transaction created the world’s largest electricity producer, combining Constellation’s nuclear fleet with Calpine’s natural gas and geothermal assets to reach a total generating capacity of 55 gigawatts. According to a press release, Constellation intends to use this combined fleet to power AI-driven data centers, advanced manufacturing facilities, and critical infrastructure that will define the AI era and secure the United States as an economic leader.
Palo Alto Networks’ Acquisition of CyberArk: $25.1 billion (Expected to Close in 2026)
In July 2025, Palo Alto Networks announced a definitive agreement to acquire CyberArk, the global leader in identity security. This deal is intended to establish a leading platform for end-to-end AI security, covering everything from managing agentic identities to enforcing security policies for AI integrations. Palo Alto Networks' management believes the emergence of AI agents is a crucial inflection point that fundamentally reshapes how identity security is delivered. The deal is expected to close in fiscal Q3 2026, having already been approved by shareholders and antitrust regulators.
Abbott’s Acquisition of Exact Science: $21 billion (Expected to Close in 2026)
In a major move to dominate the cancer diagnostics market, Abbott Laboratories announced a definitive agreement to acquire Exact Sciences (the company behind the popular Cologuard test) in November 2025. This is a “watershed moment” for the diagnostics industry, as it will result in Abbott having an indisputable edge in the cancer screening and precision oncology market. This will be the largest ever deal in the diagnostics sector and the largest healthcare deal in the last two years.
Exact Sciences is expected to become Abbott’s subsidiary and maintain its separate product portfolio and headquarters. The all-cash deal is currently moving through the standard regulatory and shareholder approval processes.
Johnson & Johnson’s Acquisition of Intra-Cellular Therapies: $14.6 billion (Closed in April 2025)
This deal was originally announced in January 2025 and closed much earlier than market expectations. The deal was structured as an all-cash merger to bolster JNJ’s innovative medicine segment, specifically within its neuroscience portfolio. The primary driver for the acquisition was CAPLYTA (lumateperone), an oral, once-daily drug for psychiatric and neurologic conditions that was developed by Intra-Cellular Therapies.
JNJ projects that CAPLYTA has the potential to reach $5 billion in annual peak sales. Additionally, the deal brought in clinical-stage programs to JNJ targeting generalized anxiety disorder, Alzheimer’s disease-related psychosis, and agitation. This deal has solidified JNJ’s leadership in the neuropsychiatry space.
Novartis’ Acquisition of Avidity Biosciences: $12 billion (Expected to Close in 2026)
In October 2025, Novartis entered into a definitive agreement to acquire Avidity Biosciences, but the deal is currently still pending shareholder and regulatory approval. Before the merger closes, Avidity must complete the separation of its early-stage precision cardiology programs and certain collaboration agreements into a new, independent public company called Atrium Therapeutics, Inc. ("SpinCo").
The acquisition strengthens Novartis’ neuroscience franchise by adding Avidity’s proprietary Antibody Oligonucleotide Conjugates platform. This platform combines monoclonal antibodies with RNA therapeutics to target diseases in muscle tissue, which has historically been difficult to reach. For Novartis, the acquired assets are expected to unlock multiple multi-billion dollar opportunities with no Loss of Exclusivity before at least 2042.
Related Reading: Largest Pharmaceutical Companies by Market Cap
Fifth Third Bancorp’s Acquisition of Comerica Inc: $10.9 billion (Expected to Close in 2026)
In October 2025, Fifth Third Bancorp and Comerica Inc entered into a definitive merger agreement, under which Fifth Third will acquire Comerica in an all-stock transaction. This was the largest US bank merger of 2025 and is expected to close by the end of Q1 2026. It has already been approved by stakeholders and is currently awaiting regulatory approval.
According to a press release, Fifth Third’s management expects the merger to accelerate its long-term growth plan by enhancing scale and geographic reach. The combined entity will operate in 17 of the 20 fastest-growing U.S. markets, significantly increasing density in Texas, California, and the Southeast.
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