At the midpoint of 2025, the U.S. mergers and acquisitions market is doing something very Wall Street: sending two messages at once. Headline deal value is climbing, megadeals are back in the conversation, private equity firms are under pressure to put capital to work, and corporate buyers are hunting for technology, scale, and resilience. Yet total transaction volume remains uneven, financing is still expensive by pre-2022 standards, and tariff uncertainty has made some boards reach for the pause button just as quickly as the calculator.
U.S. M&A Activity Is Surging in Value, Not Everywhere in Volume
The strongest evidence of a rebound is in dollar value. S&P Global Market Intelligence reported that U.S. M&A deal value reached about $383.1 billion in the first quarter of 2025, up 29.7% from the prior quarter and 2% from a year earlier. March alone accounted for roughly $339.8 billion of announced value, the strongest monthly figure since May 2022. In other words, a relatively small number of very large transactions did a lot of the heavy lifting.
PwC’s midyear analysis told a similar story globally: deal values rose 15% in the first half of 2025 compared with the first half of 2024, while deal volumes fell 9%. The Americas accounted for an estimated $908 billion of first-half deal value, or 61% of the global total. BCG, using a different methodology and transaction universe, also found North America dominating global activity and noted that large transactions remained central to the market.
Megadeals Are Setting the Tone for H2 2025
Large transactions have become the clearest signal of renewed confidence. PwC counted 36 global megadeals valued above $5 billion during the first five months of 2025, compared with 31 in the same period of 2024. It also highlighted three proposed transactions that captured the market’s direction: Google’s approximately $32 billion acquisition of Wiz, Constellation Energy’s roughly $26.6 billion acquisition of Calpine, and Global Payments’ approximately $24.25 billion acquisition of Worldpay.
These deals are not random trophy purchases. They point to three major strategic themes: cybersecurity and AI-era technology capabilities, soaring electricity demand and power infrastructure, and consolidation in payments and financial technology. The common thread is urgency. Buyers are using M&A to acquire capabilities, capacity, customers, or infrastructure faster than they could build them organically.
For H2 2025, that favors companies with scarce assets, defensible technology, recurring revenue, strong free cash flow, or a clear role in an industry’s consolidation map. Buyers may tolerate a rich price when the strategic logic is obvious. They are much less forgiving when the pitch deck requires twelve arrows, four buzzwords, and a heroic assumption about 2028 margins.
Why Dealmakers Still Expect a Stronger Second Half
1. Corporate and Private Equity Confidence Remains Resilient
KPMG’s midyear M&A pulse found that 77% of corporate respondents and 70% of private equity respondents expected U.S. M&A activity in 2025 to exceed 2024 levels. Nearly two-thirds had already changed their deal plans since the beginning of the year, showing that confidence did not disappear when policy uncertainty increased; it simply became more tactical.
Deloitte’s 2025 M&A Trends Survey was also upbeat. Among 1,500 U.S.-based corporate and private equity executives, 79% of corporate leaders and 87% of PE leaders expected their deal volume to increase over the following 12 months. Nearly three-quarters expected average deal size or value to rise. The message is clear: executives still see M&A as a growth tool, but they are narrowing their target lists and demanding stronger strategic fit.
2. Private Equity Has Capital, Aging Assets, and a Liquidity Problem
Private equity remains one of the biggest potential engines for H2 deal activity. Morgan Stanley entered 2025 pointing to nearly $3 trillion in uncommitted capital across private markets and emphasizing the unusually high age of sponsor-owned portfolios. Funds need exits to return cash to limited partners, improve distributions, and support future fundraising. At the same time, they still have enormous buying power.
PwC reported that estimated global PE buyout volume rose in the first quarter of 2025 versus a year earlier, while buyout value increased sharply. Exit value also improved. But the pressure has not vanished. J.P. Morgan Asset Management noted that private equity secondary transactions reached about $103 billion in the first half of 2025 after totaling $162 billion in the prior year, illustrating how sponsors and investors are increasingly using secondary markets when traditional exits remain difficult.
In H2, expect more continuation vehicles, minority investments, carve-outs, sponsor-to-sponsor transactions, take-privates, and structured deals. The old formula of “buy, add leverage, wait, sell at a higher multiple” is having a midlife crisis. Operational improvement is doing more of the work now.
3. AI Is Both a Target Category and a Reason to Acquire
Artificial intelligence is no longer confined to technology-sector M&A. Companies in financial services, industrials, healthcare, media, professional services, and consumer markets are evaluating acquisitions that can accelerate automation, data capabilities, cybersecurity, software modernization, or AI-enabled products.
Bain’s 2025 M&A work emphasized that technology buyers increasingly need both revenue and cost synergies, with AI tools becoming part of the value-creation playbook. EY likewise noted that industrial companies are using acquisitions to pursue AI integration, supply-chain resilience, and growth. The H2 implication is straightforward: a target does not need “AI” in its name to benefit from AI-driven demand. It may simply own the data, infrastructure, engineering talent, workflow, or customer access that an acquirer needs.
Interest Rates Matter, but They Are No Longer the Only Gatekeeper
The Federal Reserve’s rate path remains a major variable because acquisition financing is highly sensitive to the cost of debt. Lower rates would improve leveraged buyout economics, reduce interest expense, support higher valuations, and help buyers and sellers close valuation gaps. KPMG’s midyear research specifically identified a potential 50-basis-point decline in rates as a possible boost to deal activity.
Still, dealmakers are becoming less willing to wait for perfect monetary conditions. Goldman Sachs and Morgan Stanley both entered 2025 expecting improved capital-market conditions and a more constructive M&A environment, while also warning that tariffs and other policy variables could create volatility. That mindset is increasingly visible in actual transactions: strategic buyers with strong balance sheets can move even when rate clarity is incomplete.
For H2 2025, financing availability may matter more than the exact timing of one rate cut. The market does not need money to be cheap; it needs debt and equity capital to remain available at prices buyers can underwrite.
Tariffs and Trade Policy Are the Biggest Wild Card
Tariff uncertainty became one of the defining obstacles to dealmaking in the first half of 2025. It complicates revenue forecasts, input costs, supply chains, working-capital assumptions, and cross-border valuation. S&P Global connected early-2025 market volatility directly to trade concerns, while KPMG found that most dealmakers still viewed the administration’s overall policy direction as potentially positive for M&A because of expectations for a more permissive antitrust environment and changes in tax policy.
This creates a strange combination: regulation may become easier in some areas while business forecasting becomes harder in others. That is why H2 due diligence will need more scenario analysis. A serious buyer should test tariff exposure by product, supplier, geography, customer segment, and contractual pass-through ability. “We will raise prices” is not a model. It is a sentence.
Sectors Likely to Lead U.S. M&A in H2 2025
Technology and Cybersecurity
Technology remains a major center of gravity, particularly around cybersecurity, cloud infrastructure, AI tooling, data assets, vertical software, and automation. Scarce high-quality assets can still command premium valuations because strategic buyers are competing against the cost and time required to build equivalent capabilities internally.
Power, Utilities, and Energy Infrastructure
Electricity demand from data centers, AI infrastructure, manufacturing reshoring, and electrification is increasing strategic interest in generation and grid-related assets. Constellation Energy’s proposed Calpine acquisition illustrates how scale, generation capacity, and power-market positioning can become strategic priorities. Traditional energy consolidation also remains active where buyers can create operational or basin-level efficiencies.
Financial Services and Payments
Financial services continues to face pressure for scale, digital modernization, and operating efficiency. PwC found global financial-services deal value up roughly 15% in the first half of 2025 even as volume edged lower. Payments, insurance, wealth management, asset management, and selected banking combinations remain fertile ground for deals where technology spending and compliance costs reward scale.
Industrials and Advanced Manufacturing
Industrials may see more strategic transactions tied to reshoring, supply-chain security, automation, aerospace and defense technology, and specialized manufacturing. BCG found industrials among the strongest sectors for first-half deal-value growth compared with the prior six months. Buyers are increasingly willing to acquire capabilities that reduce supply-chain vulnerability or shorten the path to new markets.
What Could Derail the H2 2025 M&A Rebound?
The bullish case is not bulletproof. The biggest risks are a renewed inflation shock, persistently high long-term rates, a deterioration in credit markets, more aggressive trade measures, geopolitical escalation, weaker corporate earnings, or an equity-market correction that widens valuation gaps again. Regulatory review may also remain unpredictable in sensitive industries even if the broader tone becomes more deal-friendly.
There is also a simpler risk: buyers overpay because they are afraid of missing the cycle. McKinsey’s 2025 M&A outlook argued that powerful forces favor a rebound, particularly in North America, but the basic discipline of value creation still applies. A good market does not rescue a bad deal thesis. Sometimes the smartest acquisition is the one left in the data room.
H2 2025 Outlook: A Selective Boom, Not a Free-for-All
The most likely path for U.S. M&A in the second half of 2025 is continued strength in aggregate deal value, supported by megadeals, strategic technology acquisitions, energy and infrastructure investment, private equity pressure to transact, and corporate portfolio reshaping. Middle-market activity should improve if financing conditions become friendlier and tariff policy becomes easier to model, but a broad return to boom-era transaction volume is less certain.
Citizens entered 2025 with dealmaker sentiment at a five-year high: 54% of surveyed middle-market and private equity leaders described the M&A environment as strong, while 64% of PE respondents expected deal flow to increase. That optimism has been tested, not erased. The second half belongs to buyers and sellers that can price uncertainty rather than pretend it does not exist.
Conclusion
U.S. merger and acquisition activity in 2025 is best described as a high-value recovery with selective participation. Big strategic transactions are back, private equity has strong incentives to buy and sell, and AI is reshaping acquisition priorities across industries. At the same time, tariffs, financing costs, geopolitical risk, and valuation discipline are keeping deal teams cautious.
For H2 2025, the winners are unlikely to be the companies that wait for every macroeconomic light to turn green. They will be the ones that know exactly what they need to buy, understand how the asset creates value under multiple economic scenarios, secure financing early, and prepare integration before the champagne is ordered. In this market, conviction mattersbut spreadsheets still get the final vote.
Experience-Based Lessons for Deal Teams in H2 2025
Looking across recent M&A cycles, one practical lesson stands out: the best deal teams do not confuse market momentum with permission to relax standards. When activity accelerates, internal pressure rises. CEOs see competitors announcing acquisitions. Boards worry that scarce assets will disappear. Sellers point to the largest headline multiples and suddenly every business believes it is “strategic.” Experienced teams respond by becoming more disciplined, not less.
The first useful habit is to define the deal thesis before management falls in love with the target. A strong thesis should fit on a page and answer a few uncomfortable questions: What capability, customer base, market position, or cost advantage are we buying? Why is acquisition better than partnership or internal investment? What must be true for the return to work? If the answer depends mostly on multiple expansion, heroic growth, or “synergies to be identified later,” the team is not finished.
Second, experienced buyers model uncertainty explicitly. In H2 2025, that means building tariff, interest-rate, supply-chain, and demand scenarios into valuation rather than hiding them in a generic sensitivity table. A manufacturer with imported components may deserve different assumptions from a domestic software company. A cross-border deal may need contractual protections that would be unnecessary in a purely U.S. transaction. The point is not to predict Washington perfectly. Nobody gets a trophy for that. The goal is to know how much uncertainty the economics can absorb.
Third, financing should be treated as part of strategy, not an administrative step after price is agreed. Buyers that line up bank financing, private credit alternatives, equity capacity, and hedging options early can negotiate with more confidence. This is especially important for private equity, where a small change in debt cost can materially alter returns. Having two viable financing paths can also prevent a promising transaction from becoming hostage to one volatile week in capital markets.
Fourth, experienced dealmakers start integration planning during diligence. Technology architecture, customer retention, sales incentives, leadership roles, cultural friction, and data migration can destroy value faster than a beautifully formatted merger announcement can create it. For AI-related acquisitions, retaining key technical talent may matter as much as the code itself. For scale deals, removing duplicated costs without disrupting revenue requires a detailed Day 1 and Day 100 plan.
Finally, strong teams know when to walk away. In a rising M&A market, losing an auction can feel painful for about 48 hours. Overpaying can remain painful for years. H2 2025 may reward speed, but it should reward prepared speed: clear strategy, fast diligence, financing certainty, realistic synergies, and integration readiness. That combination is less glamorous than chasing every hot asset, but it is usually how acquisitions become returns instead of expensive corporate souvenirs.
