Table 128 Aug 2026From “The megadeal wave meets the size effect”

The megadeal evidence is a regime map

The source versions, thresholds, periods, and outcomes differ. The current row describes activity, while the academic rows describe distinct return, completion, operating, and wealth questions.

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Table 1The megadeal evidence is a regime map

Source and period	Sample and threshold	Outcome	What the row permits
Moeller et al. 2004, published	12,023 US acquisitions, 1980-2001; above US\$1 million	Three-day announcement CAR; 2.318% small versus 0.076% large acquirers	An older equal-weighted acquirer-size comparison
Alexandridis et al. 2017, accepted manuscript	26,078 US deals, 1990-2015; mega-deals at US\$500 million	Post-2009 mega-deal abnormal return of 2.54% and reported US\$62.3 million shareholder gain	A later-period accepted-manuscript comparison
Hu et al. 2020, accepted manuscript	3,544 US deals, 1980-2016; above US\$500 million in 2016 dollars	Completion, three-day CAR, 36-month stock return, and ROA by prior experience	A moderator map, not a causal guarantee
Moeller et al. 2005, published	Lower-tail analysis of large acquisitions, including 87 large-loss deals	About US\$397 billion of aggregate dollar loss	A dollar-weighted tail warning
PwC 2025, H1 activity frame	Global announced deals; megadeals above US\$5 billion; first five months extrapolated	Values up 15%, volumes down 9%, 36 versus 31 megadeals	A dated activity description, not a return estimate

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Source: Author's synthesis of Moeller, Schlingemann, and Stulz (2004, 2005), Alexandridis, Antypas, and Travlos (2017 accepted manuscript), Hu, Li, Li, and Wang (2020 accepted manuscript), and PwC (2025). The rows are not pooled and have no common y-axis.

PNG4:3, 1600 × 1200, with the title, the source line and the attribution set in the image isoglu-2026-the-megadeal-wave-meets-the-size-effect-fig01.png

Source and evidence

Each line names a claim related to this exhibit, its source, and how it was checked.

A P03-C1 Moeller, Schlingemann and Stulz, verbatim: "We examine a sample of 12,023 acquisitions by public firms from 1980 to 2001", where "The equally weighted abnormal announcement return is 1.1%, but acquiring-firm shareholders lose $25.2 million on average upon announcement", and "The announcement return for acquiring-firm shareholders is roughly two percentage points higher for small acquirers"Moeller, Schlingemann & Stulz. (2004)
B P03-C2 The accepted manuscript of Alexandridis, Antypas, and Travlos reports a post-2009 mega-deal comparison with a 2.54% abnormal return and a reported US$62.3 million shareholder gainAlexandridis, Antypas & Travlos. (2017, accepted manuscript)
B P03-C3 The accepted manuscript of Hu, Li, Li, and Wang studies 3,544 US deals above US$500 million in 2016 dollars and separates completion, three-day CAR, 36-month stock return, and ROA by prior experienceHu, Li, Li & Wang. (2020, accepted manuscript)
A P03-C4 Moeller, Schlingemann, and Stulz document concentration of large dollar losses, including 87 large-loss deals accounting for about US$397 billion in the lower-tail analysisMoeller, Schlingemann & Stulz. (2005)
B P03-C5 PwC reports that between the compared H1 2024 and H1 2025 first-five-month periods, deal values increased 15%, volumes decreased 9%, and megadeals numbered 36 versus 31PwC. (2025)
B P03-C6 PwC's H1 2025 frame is descriptive and bounded by its global announced-deal method, first-five-month extrapolation, and greater-than-US$5-billion megadeal thresholdPwC. (2025)

Grades: A, verified against the printed page of the primary source · B, primary source, text layer only · C, authoritative secondary · D, reported.

From the essay

Growth that compounds

The megadeal wave meets the size effect

Large deals are back in the market. Older size evidence, newer mega-deal research, and 2025 activity data answer three different questions.

28 Aug 2026

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APA 7

Isoglu, S. (2026). The megadeal evidence is a regime map [Table]. isoglu.com. https://isoglu.com/insights/exhibits/isoglu-2026-the-megadeal-wave-meets-the-size-effect-fig01/

BibTeX

@misc{isoglu-2026-the-megadeal-wave-meets-the-size-effect-fig01,
  author = {Isoglu, Sinan},
  title = {{The megadeal evidence is a regime map}},
  year = {2026},
  howpublished = {Table 1, isoglu.com},
  url = {https://isoglu.com/insights/exhibits/isoglu-2026-the-megadeal-wave-meets-the-size-effect-fig01/},
  note = {From the essay {The megadeal wave meets the size effect}}
}

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    <img src="https://isoglu.com/social/isoglu-2026-the-megadeal-wave-meets-the-size-effect-fig01.png" alt="Table 1: The megadeal evidence is a regime map" width="3200" height="2400">
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  <figcaption>Table 1: The megadeal evidence is a regime map. Source: Author&#39;s synthesis of Moeller, Schlingemann, and Stulz (2004, 2005), Alexandridis, Antypas, and Travlos (2017 accepted manuscript), Hu, Li, Li, and Wang (2020 accepted manuscript), and PwC (2025). The rows are not pooled and have no common y-axis. <a href="https://isoglu.com/insights/exhibits/isoglu-2026-the-megadeal-wave-meets-the-size-effect-fig01/">View exhibit</a>.</figcaption>
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