Arch Capital Group Ltd.
Arch Capital Group Ltd. (ACGL) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · ACGL · as of Sep 30, 2025
Ownership Breakdown
857
Institutional Holders
▼ 13 vs Q2
$29.65B
Total Inst. Value
▼ $954.46M vs Q2
349.39M
Shares Outstanding
freeFloat 96.37%
326.42M
13F Shares Held
▼ 9.90M vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
ACGL largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
VANGUARD GROUP INC fire, marine & casualty insurance | 42.31M | 11.37% | 11.37% | $3.84T | Nov 7, 2025 | ▼ 101.3K |
BLACKROCK, INC. fire, marine & casualty insurance | 32.46M | 8.72% | 8.72% | $2.95T | Nov 12, 2025 | ▼ 463.7K |
ARTISAN PARTNERS LIMITED PARTNERSHIP fire, marine & casualty insurance | 23.64M | 6.35% | 6.35% | $2.14T | Nov 12, 2025 | ▼ 195.2K |
BAMCO INC /NY/ fire, marine & casualty insurance | 18.76M | 5.04% | 5.04% | $1.70T | Nov 14, 2025 | ▼ 967.6K |
STATE STREET CORP fire, marine & casualty insurance | 16.77M | 4.51% | 4.51% | $1.52T | Nov 14, 2025 | ▼ 177.0K |
WCM INVESTMENT MANAGEMENT, LLC fire, marine & casualty insurance | 13.53M | 3.63% | 3.63% | $1.21T | Nov 4, 2025 | ▲ 171.7K |
GEODE CAPITAL MANAGEMENT, LLC fire, marine & casualty insurance | 10.69M | 2.87% | 2.87% | $966.63B | Nov 12, 2025 | ▲ 191.7K |
JPMORGAN CHASE & CO fire, marine & casualty insurance | 8.19M | 2.20% | 2.20% | $743.17B | Nov 26, 2025 | ▲ 360.6K |
PRINCIPAL FINANCIAL GROUP INC fire, marine & casualty insurance | 5.15M | 1.38% | 1.38% | $467.12B | Nov 4, 2025 | ▼ 687.4K |
NORTHERN TRUST CORP fire, marine & casualty insurance | 4.87M | 1.31% | 1.31% | $442.23B | Nov 14, 2025 | ▼ 935 |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
25
Increased
+10.33M shares1
New Positions
first time holders24
Decreased
−14.01M shares0
Sold Out
fully exitedNet shares change (top 50)
3.68M
+10.33M / −14.01M
Net new holders
+2
1 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
ACGL insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
17
Buy transactions
2
Sell transactions
8.50
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Posner Brian S director | Jun 3, 2026 | Sale | 3,000 | $19.66 | $59.0K | 0 | Form 4 ↗ |
Posner Brian S director | May 11, 2026 | Sale | 2,000 | $17.14 | $34.3K | 0 | Form 4 ↗ |
Triplett Neal F director | May 5, 2026 | Award | 1,327 | — | — | 8.0K | Form 4 ↗ |
Triplett Neal F director | May 5, 2026 | Award | 2,071 | — | — | 6.7K | Form 4 ↗ |
Posner Brian S director | May 5, 2026 | Award | 2,071 | — | — | 122.2K | Form 4 ↗ |
MOCZARSKI ALEXANDER S director | May 5, 2026 | Award | 2,071 | — | — | 4.0K | Form 4 ↗ |
MALLESCH EILEEN A director | May 5, 2026 | Award | 2,071 | — | — | 13.8K | Form 4 ↗ |
KILCOYNE MOIRA A. director | May 5, 2026 | Award | 1,327 | — | — | 35.8K | Form 4 ↗ |
KILCOYNE MOIRA A. director | May 5, 2026 | Award | 2,071 | — | — | 34.5K | Form 4 ↗ |
Houston Daniel Joseph director | May 5, 2026 | Award | 1,327 | — | — | 13.3K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Arch Capital Group Ltd. (ACGL) is primarily owned by institutional investors, who hold approximately 93.4% of total shares outstanding. Company insiders own approximately 3.63%, while retail and public investors account for the remaining 2.95%.
The largest institutional shareholder of Arch Capital Group Ltd. is VANGUARD GROUP INC, holding approximately 42.31 million shares — equal to 11.37% of outstanding shares — as of September 30, 2025.
A total of 857 institutional investors currently hold ACGL stock, with a combined institutional value of approximately $29.65 billion as of the most recent 13F filing period.
Frequently asked questions
ACGL ownershipArch Capital Group Ltd. (ACGL) is primarily owned by institutional investors, who hold approximately 93.4% of shares. The largest shareholder is VANGUARD GROUP INC with a 11.37% stake. Company insiders hold 3.63%. Data sourced from SEC Form 13F as of September 30, 2025.