Great Lakes Dredge & Dock Corporation
US ˙ NasdaqGS ˙ US3906071093
TEN SYMBOL NIE JEST JUŻ AKTYWNY

SecurityGLDD / Great Lakes Dredge & Dock Corporation
InstitutionBlackRock, Inc.
Latest Disclosed Ownership6,701,811 shares
Ownership 10.00%
BlackRock, Inc. ownership in GLDD / Great Lakes Dredge & Dock Corporation

2026-03-04 - BlackRock, Inc. has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 6,701,811 shares of Great Lakes Dredge & Dock Corporation (US:GLDD). This represents 10.0 percent ownership of the company. In their previous filing dated 2025-04-24 , BlackRock, Inc. had reported owning 6,708,250 shares, indicating a decrease of -0.10 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date		Effective
Date		Form Prev
Shares		 Latest
Shares		 ΔShares
(Percent)		 Ownership
(Percent)		 ΔOwnership
(Percent)
2026-03-04 2026-03-04 13G/A 6,708,250 6,701,811 -0.10 10.00 0.50
2025-04-24 2025-04-24 13G/A 7,403,096 6,708,250 -9.39 9.95 -10.36
2024-01-24 2024-01-24 13G/A 6,802,165 7,403,096 8.83 11.10 7.77
2023-04-06 2023-04-06 13G/A 6,397,494 6,802,165 6.33 10.30 6.19
2023-01-24 2023-01-24 13G/A 5,149,635 6,397,494 24.23 9.70 24.36
2022-02-03 2022-02-03 13G/A 4,997,232 5,149,635 3.05 7.80 1.30
2021-01-29 2021-01-29 13G/A 4,515,670 4,997,232 10.66 7.70 8.45
2020-02-05 2020-02-05 13G/A 4,280,035 4,515,670 5.51 7.10 2.90
2019-02-04 2019-02-04 13G/A 3,772,579 4,280,035 13.45 6.90 13.11
2018-01-25 2018-01-25 13G/A 3,887,915 3,772,579 -2.97 6.10 -4.69
2017-01-24 2017-01-24 13G/A 3,887,915 3,887,915 0.00 6.40 0.00
2017-01-23 2017-01-23 13G/A 3,416,514 3,887,915 13.80 6.40 12.28
2016-01-26 2016-01-26 13G/A 3,416,514 5.70
2015-02-02 2015-02-02 13G/A 3,493,731 5.80
2014-01-29 2014-01-29 13G/A 3,492,353 5.90
2013-02-08 2013-02-08 13G/A 3,199,863 5.40
2012-02-13 2012-02-13 13G/A 3,179,562 5.39

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

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 GREAT LAKES DREDGE & DOCK COM 390607109 5,917,589 -979,626 -14.20 100,599 11.17 0.0001
2026-02-12 2025-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 6,897,215 -40,505 -0.58 90,491 8.79 0.0015
2025-11-12 2025-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 6,937,720 152,598 2.25 83,183 0.57 0.0015
2025-08-12 2025-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 6,785,122 -378,765 -5.29 82,711 32.71 0.0016
2025-05-02 2025-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 7,163,887 50,134 0.70 62,326 -22.40 0.0013
2025-02-07 2024-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 7,113,753 -101,451 -1.41 80,314 5.71 0.0016
2024-11-13 2024-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 7,215,204 302,718 4.38 75,976 25.18 0.0016
2024-08-13 2024-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 6,912,486 285,331 4.31 60,692 4.66 0.0014
2024-05-10 2024-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 6,627,155 -775,941 -10.48 57,988 1.99 0.0013
2024-02-13 2023-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 7,403,096 634,549 9.37 56,856 5.39 0.0014
2023-11-13 2023-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 6,768,547 49,934 0.74 53,945 -1.60 0.0016
2023-08-11 2023-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 6,718,613 -83,552 -1.23 54,824 48.43 0.0015
2023-05-12 2023-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 6,802,165 404,671 6.33 36,936 -2.97 0.0011
2023-02-13 2022-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 6,397,494 716,193 12.61 38,065 -11.61 0.0012
2022-11-14 2022-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 5,681,301 154,218 2.79 43,064 -40.57 0.0015
2022-08-12 2022-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 5,527,083 422,578 8.28 72,459 1.18 0.0023
2022-05-12 2022-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 5,104,505 -45,130 -0.88 71,614 -11.54 0.0019
2022-02-10 2021-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 5,149,635 -87,884 -1.68 80,952 2.43 0.0021
2021-11-09 2021-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 5,237,519 -236,675 -4.32 79,033 -1.18 0.0022
2021-08-11 2021-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 5,474,194 -24,707 -0.45 79,978 -0.24 0.0022
2021-05-07 2021-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 5,498,901 501,669 10.04 80,173 21.82 0.0024
2021-02-05 2020-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 4,997,232 358,912 7.74 65,814 49.20 0.0021
2020-11-06 2020-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 4,638,320 -180,438 -3.74 44,111 -1.15 0.0016
2020-08-14 2020-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 4,818,758 142,119 3.04 44,622 14.96 0.0018
2020-05-01 2020-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 4,676,639 160,969 3.56 38,816 -24.13 0.0019
2020-02-13 2019-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 4,515,670 -10,881 -0.24 51,163 8.16 0.0020
2019-11-08 2019-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 4,526,551 194,812 4.50 47,302 -1.09 0.0020
2019-08-22 2019-06-30 13F/A-1 GREAT LAKES DREDGE & DOCK COM 390607109 4,331,739 173,882 4.18 47,823 29.09 0.0020
2019-08-13 2019-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 4,331,739 173,882 47,823
2019-05-09 2019-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 4,157,857 -122,178 -2.85 37,046 30.75 0.0017
2019-02-08 2018-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 4,280,035 303,406 7.63 28,333 14.92 0.0014
2018-11-09 2018-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 3,976,629 26,259 0.66 24,655 18.88 0.0011
2018-08-09 2018-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 3,950,370 205,172 5.48 20,739 20.38 0.0010
2018-05-09 2018-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 3,745,198 -27,381 -0.73 17,228 -15.42 0.0008
2018-02-09 2017-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 3,772,579 23,367 0.62 20,370 12.02 0.0010
2017-11-14 2017-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 3,749,212 12,092 0.32 18,184 13.15 0.0009
2017-08-10 2017-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 3,737,120 -134,960 -3.49 16,070 3.75 0.0009
2017-05-12 2017-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 3,872,080 3,855,430 23,155.74 15,489 22,027.14 0.0009
2017-02-10 2016-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 16,650 0 0.00 70 20.69 0.0001
2016-11-08 2016-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 16,650 0 0.00 58 -20.55 0.0001
2016-08-10 2016-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 16,650 12,159 270.74 73 265.00 0.0001
2016-05-10 2016-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 4,491 2,352 109.96 20 122.22 0.0000
2016-02-11 2015-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 2,139 0 0.00 9 -18.18 0.0000
2015-11-13 2015-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 2,139 0 0.00 11 -15.38 0.0000
2015-08-07 2015-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 2,139 0 0.00 13 0.00 0.0000
2015-05-13 2015-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 2,139 0 0.00 13 -27.78 0.0000
2015-02-09 2014-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 2,139 0 0.00 18 38.46 0.0000
2014-10-29 2014-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 2,139 0 0.00 13 -23.53 0.0000
2014-08-06 2014-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 2,139 0 0.00 17 -15.00 0.0000
2014-05-02 2014-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 2,139 0 0.00 20 0.00 0.0000
2014-02-12 2013-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 2,139 0 0.00 20 25.00 0.0000
2013-11-12 2013-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 2,139 0 0.00 16 -5.88 0.0000
2013-08-13 2013-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 2,139 2,139 17 0.0000
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.