Late 2025 and early 2026 private equity deals across energy, software, cybersecurity and aerospace signal an active year ahead, with significant transactions and an upcoming Deal of the Year Awards highlighting sector momentum.
Good morning. Private equity deal activity that closed late in December and in early January points to a potentially busier 2026 for buyout firms, with large transactions across energy, software, cybersecurity and aerospace underpinning that outlook, according to PE Hub’s US Wire.
PE Hub reminded readers that entries for its Deal of the Year Awards , which will honour buyouts fully or mostly realised in 2025 , are due on Friday, January 23, 2026, with winners to be announced in March. The awards will be presented across six categories plus an overall winner, PE Hub said.
Energy consolidation and clean-power scale
The biggest headline was the combination of Calpine Corporation and Constellation, a deal PE Hub reported as a $26.6 billion transaction. According to an Energy Capital Partners statement and reporting by major outlets, the transaction comprises roughly $16.4 billion in consideration plus about $12.7 billion of net debt assumed, and will create one of the nation’s largest clean-energy providers by combining Constellation’s nuclear fleet with Calpine’s natural gas and geothermal generation. The parties said the tie-up will expand the ability to serve customers across key markets and to offer a broader array of energy and sustainability products.
Tyler Reeder, president and managing partner of Energy Capital Partners, framed the deal as consistent with the firm’s long-standing power-investing strategy: “As a decades-long investor in power generation, ECP aims to unlock value, drive long-term growth opportunities and strengthen asset reliability , often serving as a bridge between public and private markets,” he said.
Software and embedded AI for the CFO
Private equity interest in finance-focused software continued with Hg’s agreed takeover of OneStream for about $6.4 billion in cash, a transaction that will take the Birmingham, Michigan-based financial software vendor private. Under the terms, OneStream shareholders will receive $24.00 per share, a premium to the company’s early-January trading price, and the deal is expected to close in the first half of 2026 subject to customary approvals. KKR, which took OneStream public in 2024, has approved the sale; General Atlantic and Tidemark will be minority investors alongside Hg.
Alan Cline, partner and head of North America at Hg, positioned the acquisition around AI-driven finance automation: “With over $4.5 billion invested in providers that serve the Office of the CFO to date, we understand the tremendous opportunity for OneStream, as technology and industry trends continue to place increasing demands on Finance teams,” he said. “To meet this need, OneStream’s powerful AI differentiation, strong global customer base and clear vision for the future of modern Finance make it a leading enterprise provider in this space and exceptionally well positioned for the future.”
Cybersecurity exit to a strategic buyer
In cybersecurity, One Equity Partners agreed to sell its stake in Armis to ServiceNow in a deal that values Armis at about $7 billion. Armis, a San Francisco-based cyber exposure management specialist founded in 2015, counts more than 40% of the Fortune 100 among its clients, including seven of the Fortune 10, the parties said. One Equity Partners credited an M&A-led expansion of Armis’s capabilities across cloud, AI and operational-technology security during its four-year investment.
“OEP’s investment in Armis illustrates our ability to identify leading-edge companies in the dynamic technology space, drive recurring revenue growth via new client acquisition and transformational M&A, and boost value in the marketplace,” said Andrew Dunn, partner at One Equity Partners.
Aerospace and defence momentum
Private equity’s momentum in aerospace and defence, a sector PE Hub said had a bumper 2025, is continuing into the new year with several notable deals that reflect aftermarket and leasing dynamics.
KKR has agreed to increase its stake in aircraft lessor Altavair and sister company AV AirFinance, extending a strategic partnership in which it has already committed more than $5 billion since 2018. Brandon Freiman, partner and head of North American infrastructure at KKR, said aircraft assets have proved resilient across cycles and that Altavair is “well positioned to execute at scale across the aviation ecosystem.”
Strategic acquirers are also active: TransDigm has agreed to buy Jet Parts Engineering and Victor Sierra Aviation Holdings from Vance Street Capital for roughly $2.2 billion in cash, reinforcing demand for aftermarket parts capacity. Meanwhile, private-equity-owned JF Lehman & Company has taken a majority stake in Wellman Dynamics, an Iowa-based supplier of magnesium and aluminium sand castings that serve critical aerospace and defence programmes.
Noah Blitzer of Greenbriar, quoted by PE Hub last year on sector drivers, highlighted aftermarket demand as a key force: “The shifting aftermarket demand is creating opportunities for new and expanded services as airlines look to lower maintenance costs and limit downtime,” he said.
What it signals for 2026
Taken together, these transactions illustrate a private equity market still capable of moving very large deals across multiple sectors, even as firms and strategic buyers weigh economic and regulatory headwinds. According to PE Hub, Blackstone’s Martin Brand and other industry voices are predicting an uptick in dealmaking in 2026; the early-January wave of energy, software, cybersecurity and aerospace transactions will be watched as potential leading indicators.
Entries for PE Hub’s Deal of the Year Awards close on January 23, 2026. The Wire will track which of these late-2025 and early-2026 transactions make the shortlist when winners are announced in March.
- https://www.pehub.com/deals-from-kkr-ecp-hg-and-oep-suggest-increased-m-deal-of-the-year-award-entries-are-due-friday/ – Please view link – unable to able to access data
- https://www.pehub.com/deals-from-kkr-ecp-hg-and-oep-suggest-increased-m-deal-of-the-year-award-entries-are-due-friday/ – PE Hub’s article highlights significant mergers and acquisitions, including Energy Capital Partners’ sale of Calpine Corporation to Constellation for $26.6 billion, Hg’s agreement to acquire OneStream for $6.4 billion, and One Equity Partners’ sale of its stake in Armis to ServiceNow, valuing the company at $7 billion. The piece also discusses recent aerospace and defense deals, noting increased private equity investments in the sector. Additionally, it reminds readers of the upcoming deadline for PE Hub’s Deal of the Year Awards, set for January 23, 2026.
- https://www.ecpgp.com/about/news-and-insights/press-releases/2025/constellation-to-acquire-calpine-creates-americas-leading-producer-of-clean-and-reliable-energy-to-meet-growing-demand-for-customers-and-communities – Energy Capital Partners (ECP) announced that Constellation will acquire Calpine Corporation in a cash and stock transaction valued at approximately $16.4 billion, with an additional $12.7 billion in net debt assumed, bringing the total to $26.6 billion. This acquisition aims to create the nation’s largest clean energy provider, combining Constellation’s nuclear fleet with Calpine’s natural gas and geothermal generation, thereby enhancing the ability to meet growing energy demand with clean and reliable solutions.
- https://www.investing.com/news/company-news/hg-to-acquire-onestream-for-64-billion-in-allcash-deal-93CH-4433257 – Hg, a leading investor in software, services, and data businesses, has agreed to acquire OneStream, Inc. in an all-cash transaction valued at approximately $6.4 billion. Under the terms, OneStream shareholders will receive $24.00 per share, representing a 31% premium to the company’s closing price on January 5, 2026. The deal is expected to close in the first half of 2026, with KKR, which took OneStream public in 2024, approving the transaction.
- https://www.nasdaq.com/articles/onestream-to-be-acquired-by-hg-64-bln – OneStream, Inc. has agreed to be acquired by Hg, a leading investor in software, services, and data businesses, in an all-cash transaction valued at about $6.4 billion. Hg will become the majority voting shareholder, with General Atlantic and Tidemark taking minority positions. Under the agreement, OneStream shareholders will receive $24.00 per share in cash, a 31% premium to the company’s closing share price on January 5, 2026. The transaction is expected to close in the first half of 2026.
- https://www.cnbc.com/2025/01/10/constellation-energy-to-buy-calpine-corp.html – Constellation Energy has agreed to acquire Calpine Corp. in a cash-and-stock deal valued at $16.4 billion, with an additional $12.7 billion in debt assumed, totaling $26.6 billion. This acquisition aims to create the nation’s leading retail electric supplier, serving 2.5 million customers across the continental U.S., including key markets like Texas, California, and New York. The combined company will have nearly 60 gigawatts of capacity from zero- and low-emission sources, including nuclear, natural gas, geothermal, hydro, wind, solar, cogeneration, and battery storage.
- https://www.onestream.com/news/onestream-enters-into-definitive-agreement-to-be-acquired-by-hg-for-usd6-4-billion/ – OneStream has entered into a definitive agreement to be acquired by Hg for $6.4 billion. The transaction, unanimously approved by OneStream’s Board of Directors, is expected to close in the first half of 2026, subject to regulatory approvals and other customary closing conditions. KKR, which holds a majority of OneStream’s voting power, has approved the transaction. Upon completion, OneStream will become a privately held company, and its Class A common stock will no longer trade on public exchanges.
Noah Fact Check Pro
The draft above was created using the information available at the time the story first
emerged. We’ve since applied our fact-checking process to the final narrative, based on the criteria listed
below. The results are intended to help you assess the credibility of the piece and highlight any areas that may
warrant further investigation.
Freshness check
Score:
7
Notes:
The article discusses recent private equity deals and mentions that entries for PE Hub’s Deal of the Year Awards are due on January 23, 2026. The earliest known publication date of similar content is January 18, 2026, indicating that the narrative is fresh. However, the article is based on a press release from PE Hub, which typically warrants a high freshness score. The narrative includes updated data but recycles older material, which raises concerns about originality.
Quotes check
Score:
6
Notes:
The article includes direct quotes from individuals such as Tyler Reeder, Alan Cline, and Andrew Dunn. However, these quotes cannot be independently verified through online searches, as no online matches are found. This lack of verifiability raises concerns about the authenticity of the quotes.
Source reliability
Score:
5
Notes:
The article originates from PE Hub, a niche publication focused on private equity. While it is reputable within its niche, it is not a major news organisation, which may limit its reach and influence. Additionally, the article appears to be summarising or aggregating content from other sources, which raises concerns about source independence.
Plausability check
Score:
7
Notes:
The article discusses recent private equity deals and mentions that entries for PE Hub’s Deal of the Year Awards are due on January 23, 2026. These claims are plausible and align with industry trends. However, the article lacks supporting detail from other reputable outlets, which raises concerns about the comprehensiveness of the information.
Overall assessment
Verdict (FAIL, OPEN, PASS): FAIL
Confidence (LOW, MEDIUM, HIGH): MEDIUM
Summary:
The article presents recent private equity deals and mentions the upcoming deadline for PE Hub’s Deal of the Year Awards. However, it relies heavily on a press release from PE Hub and includes quotes that cannot be independently verified, raising concerns about the originality and reliability of the content. The source’s limited reach and the lack of supporting detail from other reputable outlets further diminish the overall credibility.