Arch Capital Group Ltd.
US ˙ NasdaqGS ˙ BMG0450A1053

SecurityACGL / Arch Capital Group Ltd.
InstitutionBoston Partners
Latest Disclosed Ownership2,092,817 shares
Latest Disclosed Value $ 200,894,371
Boston Partners ownership in ACGL / Arch Capital Group Ltd.

On May 11, 2026 - Boston Partners filed a 13F-HR form disclosing ownership of 2,092,817 shares of Arch Capital Group Ltd. (US:ACGL) valued at $200,889,504 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 7, 2024 disclosing 0 shares of Arch Capital Group Ltd.. The current value of the position is $183,937,686 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-11 2026-03-31 13F ARCH CAP GROUP ORD G0450A105 2,092,817 2,092,817 200,894 0.0899
2024-02-07 2023-12-31 13F ARCH CAP GROUP ORD G0450A105 0 -1,690,400 -100.00 0 -100.00
2023-11-08 2023-09-30 13F ARCH CAP GROUP ORD G0450A105 1,690,400 558 0.03 134,772 6.54 0.1866
2023-08-10 2023-06-30 13F ARCH CAP GROUP ORD G0450A105 1,689,842 -349,637 -17.14 126,493 -8.65 0.1703
2023-05-09 2023-03-31 13F ARCH CAP GROUP ORD G0450A105 2,039,479 10,444 0.51 138,475 8.70 0.1904
2023-02-08 2022-12-31 13F ARCH CAP GROUP ORD G0450A105 2,029,035 609,547 42.94 127,393 96.88 0.1723
2022-11-09 2022-09-30 13F ARCH CAP GROUP ORD G0450A105 1,419,488 867,712 157.26 64,705 103.80 0.0947
2014-05-07 2014-03-31 13F ARCH CAP GROUP ORD G0450A105 551,776 -52,893 -8.75 31,749 -12.03 0.0579
2014-02-06 2013-12-31 13F ARCH CAP GROUP ORD G0450A105 604,669 137,927 29.55 36,092 42.85 0.0740
2013-11-12 2013-09-30 13F ARCH CAP GROUP ORD G0450A105 466,742 115,029 32.71 25,265 39.73 0.0609
2013-08-01 2013-06-30 13F ARCH CAP GROUP ORD G0450A105 351,713 351,713 18,081 0.0498
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.