Arch Capital Group Ltd.
US ˙ NasdaqGS ˙ BMG0450A1053

SecurityACGL / Arch Capital Group Ltd.
InstitutionNatixis Advisors, L.p.
Latest Disclosed Ownership2,331,537 shares
Latest Disclosed Value $ 223,804
Natixis Advisors, L.p. reports 8.64% increase in ownership of ACGL / Arch Capital Group Ltd.

On May 13, 2026 - Natixis Advisors, L.p. filed a 13F-HR form disclosing ownership of 2,331,537 shares of Arch Capital Group Ltd. (US:ACGL) valued at $223,804,237 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 2,146,087 shares of Arch Capital Group Ltd.. This represents a change in shares of 8.64% during the quarter. The current value of the position is $204,918,787 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)
2026-05-13 2026-03-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 2,331,537 185,450 8.64 224 8.78 0.3113
2026-02-10 2025-12-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 2,146,087 195,068 10.00 206 15.82 0.2917
2025-11-13 2025-09-30 13F ARCH CAP GROUP LTD ORD COM G0450A105 1,951,019 168,922 9.48 177 9.26 0.2583
2025-08-13 2025-06-30 13F ARCH CAP GROUP LTD ORD COM G0450A105 1,782,097 306,481 20.77 162 14.89 0.2574
2025-05-08 2025-03-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 1,475,616 258,576 21.25 142 25.89 0.2623
2025-02-10 2024-12-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 1,217,040 -16,964 -1.37 112 -18.84 0.2100
2024-11-06 2024-09-30 13F ARCH CAP GROUP COM G0450A105 1,234,004 94,524 8.30 138 21.05 0.2692
2024-08-01 2024-06-30 13F ARCH CAP GROUP LTD ORD COM G0450A105 1,139,480 423,406 59.13 115 72.73 0.2500
2024-04-25 2024-03-31 13F ARCH CAP GROUP COM G0450A105 716,074 173,728 32.03 66 65.00 0.1522
2024-02-06 2023-12-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 542,346 17,835 3.40 40 -2.44 0.1060
2023-11-13 2023-09-30 13F ARCH CAP GROUP COM G0450A105 524,511 53,051 11.25 42 17.14 0.1279
2023-08-15 2023-06-30 13F ARCH CAP GROUP LTD ORD COM G0450A105 471,460 18,783 4.15 35 16.67 0.1090
2023-05-11 2023-03-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 452,677 127,543 39.23 31 50.00 0.1057
2023-01-27 2022-12-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 325,134 -145,125 -30.86 20 -99.91 0.0772
2022-11-14 2022-09-30 13F ARCH CAP GROUP LTD ORD COM G0450A105 470,259 47,893 11.34 21,416 11.47 0.0906
2022-08-12 2022-06-30 13F ARCH CAP GROUP LTD ORD COM G0450A105 422,366 6,417 1.54 19,213 -4.60 0.0845
2022-05-12 2022-03-31 13F ARCH CAP GROUP COM G0450A105 415,949 93,984 29.19 20,140 40.73 0.0768
2022-02-08 2021-12-31 13F ARCH CAP GROUP COM G0450A105 321,965 17,463 5.73 14,311 23.09 0.0546
2021-11-15 2021-09-30 13F ARCH CAP GROUP LTD ORD COM G0450A105 304,502 13,561 4.66 11,626 2.62 0.0478
2021-08-12 2021-06-30 13F ARCH CAP GROUP COM G0450A105 290,941 11,114 3.97 11,329 5.52 0.0529
2021-05-05 2021-03-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 279,827 17,819 6.80 10,736 13.60 0.0560
2021-02-12 2020-12-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 262,008 44,352 20.38 9,451 48.46 0.0544
2020-11-12 2020-09-30 13F ARCH CAP GROUP LTD ORD COM G0450A105 217,656 55,768 34.45 6,366 37.26 0.0401
2020-08-11 2020-06-30 13F ARCH CAP GROUP LTD ORD COM G0450A105 161,888 89,907 124.90 4,638 126.35 0.0308
2020-04-27 2020-03-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 71,981 25,486 54.81 2,049 2.76 0.0167
2020-02-10 2019-12-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 46,495 3,438 7.98 1,994 10.29 0.0141
2019-11-12 2019-09-30 13F ARCH CAP GROUP LTD ORD COM G0450A105 43,057 573 1.35 1,808 14.79 0.0144
2019-08-12 2019-06-30 13F ARCH CAP GROUP COM G0450A105 42,484 990 2.39 1,575 17.45 0.0129
2019-05-15 2019-03-31 13F/A-1 ARCH CAP GROUP LTD ORD COM G0450A105 41,494 7,204 21.01 1,341 46.40 0.0117
2019-05-15 2019-03-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 41,494 7,204 1,341
2019-02-13 2018-12-31 13F/A-1 ARCH CAP GROUP LTD ORD COM G0450A105 34,290 -1,306 -3.67 916 -13.67 0.0090
2019-02-13 2018-12-31 13F ARCH CAP GROUP LTD ORD COM G0450A105 34,290 -1,306 916
2018-11-13 2018-09-30 13F ARCH CAP GROUP COM G0450A105 35,596 -2,560 -6.71 1,061 5.05 0.0093
2018-08-14 2018-06-30 13F/A-1 ARCH CAP GROUP LTD ORD COM G0450A105 38,156 27,251 249.89 1,010 8.25 0.0096
2018-08-14 2018-06-30 13F ARCH CAP GROUP LTD ORD COM G0450A105 38,156 1,010
2018-05-10 2018-03-31 13F ARCH CAP GROUP COM G0450A105 10,905 -945 -7.97 933 -13.21 0.0092
2018-02-14 2017-12-31 13F ARCH CAP GROUP COM G0450A105 11,850 1,823 18.18 1,075 8.92 0.0109
2017-11-14 2017-09-30 13F ARCH CAP GROUP COM G0450A105 10,027 10,027 987 0.0104
2017-05-12 2017-03-31 13F ARCH CAP GROUP COM G0450A105 0 -10,042 -100.00 0 -100.00
2017-02-07 2016-12-31 13F ARCH CAP GROUP COM G0450A105 10,042 10,042 0.00 867 0.0104
2016-11-04 2016-09-30 13F ARCH CAP GROUP LTD ORD G0450A105 0 -10,202 -100.00 0 -100.00
2016-08-01 2016-06-30 13F ARCH CAP GROUP LTD ORD G0450A105 10,202 10,202 735 0.0102
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.