Great Lakes Dredge & Dock Corporation
US ˙ NasdaqGS ˙ US3906071093
DETTE SYMBOL ER IKKE LÆNGERE AKTIVT

SecurityGLDD / Great Lakes Dredge & Dock Corporation
InstitutionRhumbline Advisers
Latest Disclosed Ownership87,855 shares
Latest Disclosed Value $ 1,493,535
Rhumbline Advisers reports 1.72% decrease in ownership of GLDD / Great Lakes Dredge & Dock Corporation

On May 12, 2026 - Rhumbline Advisers filed a 13F-HR form disclosing ownership of 87,855 shares of Great Lakes Dredge & Dock Corporation (US:GLDD) valued at $1,493,535 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 89,395 shares of Great Lakes Dredge & Dock Corporation. This represents a change in shares of -1.72% during the quarter. The current value of the position is $1,493,535 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)
2026-05-12 2026-03-31 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 87,855 -1,540 -1.72 1,494 27.39 0.0013
2026-02-13 2025-12-31 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 89,395 -15,225 -14.55 1,173 -6.54 0.0009
2025-11-06 2025-09-30 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 104,620 -2,363 -2.21 1,254 -3.83 0.0010
2025-08-12 2025-06-30 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 106,983 4,673 4.57 1,304 46.52 0.0011
2025-05-29 2025-03-31 13F/A-1 GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 102,310 -4,258 -4.00 890 -26.02 0.0008
2025-04-08 2025-03-31 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 102,310 -4,258 890 0.0008
2025-05-29 2024-12-31 13F/A-1 GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 106,568 -415 -0.39 1,203 6.84 0.0011
2025-01-30 2024-12-31 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 106,568 -415 1,203 0.0011
2024-11-12 2024-09-30 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 106,983 -1,970 -1.81 1,127 17.78 0.0010
2024-08-01 2024-06-30 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 108,953 247 0.23 957 0.53 0.0009
2024-05-09 2024-03-31 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 108,706 105 0.10 951 14.03 0.0009
2024-02-08 2023-12-31 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 108,601 910 0.85 834 -2.80 0.0009
2023-11-09 2023-09-30 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 107,691 3,030 2.90 858 0.47 0.0010
2023-08-08 2023-06-30 13F GREAT LAKES DREDGE & DOCK CORP NEW COM COM 390607109 104,661 6,640 6.77 854 0.0010
2023-05-11 2023-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 98,021 1,212 1.25 1 -100.00 0.0007
2023-02-14 2022-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 96,809 759 0.79 576 -20.88 0.0008
2022-11-10 2022-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 96,050 5,809 6.44 728 -38.46 0.0011
2022-08-11 2022-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 90,241 2,022 2.29 1,183 -4.44 0.0017
2022-05-12 2022-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 88,219 -8,342 -8.64 1,238 -18.45 0.0016
2022-02-10 2021-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 96,561 -969 -0.99 1,518 3.13 0.0019
2021-11-12 2021-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 97,530 2,470 2.60 1,472 5.98 0.0020
2021-08-05 2021-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 95,060 -9,425 -9.02 1,389 -8.80 0.0018
2021-05-06 2021-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 104,485 -6,443 -5.81 1,523 4.24 0.0021
2021-02-10 2020-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 110,928 13,381 13.72 1,461 57.44 0.0020
2020-11-12 2020-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 97,547 -13,534 -12.18 928 -9.82 0.0015
2020-08-13 2020-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 111,081 28,925 35.21 1,029 50.88 0.0017
2020-05-06 2020-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 82,156 71 0.09 682 -26.67 0.0014
2020-02-05 2019-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 82,085 939 1.16 930 9.67 0.0016
2019-10-23 2019-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 81,146 461 0.57 848 -4.83 0.0015
2019-08-14 2019-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 80,685 -376 -0.46 891 23.41 0.0017
2019-05-01 2019-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 81,061 -36 -0.04 722 34.45 0.0014
2019-01-31 2018-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 81,097 23,952 41.91 537 51.69 0.0012
2018-11-07 2018-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 57,145 90 0.16 354 18.00 0.0007
2018-08-06 2018-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 57,055 835 1.49 300 15.83 0.0006
2018-05-02 2018-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 56,220 -2,800 -4.74 259 -18.81 0.0005
2018-02-09 2017-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 59,020 -8,320 -12.36 319 -2.45 0.0006
2017-11-06 2017-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 67,340 575 0.86 327 13.94 0.0007
2017-08-02 2017-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 66,765 -6,605 -9.00 287 -2.05 0.0007
2017-05-02 2017-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 73,370 2,499 3.53 293 -1.68 0.0007
2017-01-27 2016-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 70,871 1,876 2.72 298 23.65 0.0008
2016-11-08 2016-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 68,995 -400 -0.58 241 -20.46 0.0007
2016-08-11 2016-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 69,395 -21,585 -23.72 303 -25.37 0.0009
2016-05-02 2016-03-31 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 90,980 7,725 9.28 406 23.03 0.0013
2016-02-03 2015-12-31 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 83,255 3,760 4.73 330 -17.71 0.0011
2015-11-04 2015-09-30 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 79,495 557 0.71 401 -14.68 0.0014
2015-08-04 2015-06-30 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 78,938 -8,825 -10.06 470 -10.82 0.0015
2015-05-12 2015-03-31 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 87,763 5,000 6.04 527 -25.56 0.0015
2015-02-06 2014-12-31 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 82,763 6,725 8.84 708 50.64 0.0021
2014-11-12 2014-09-30 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 76,038 1,100 1.47 470 -21.54 0.0014
2014-08-06 2014-06-30 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 74,938 -3,102 -3.97 599 -15.99 0.0018
2014-05-06 2014-03-31 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 78,040 -2,700 -3.34 713 -4.04 0.0021
2014-02-03 2013-12-31 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 80,740 -4,950 -5.78 743 16.82 0.0022
2013-11-05 2013-09-30 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 85,690 -532 -0.62 636 -5.64 0.0020
2013-08-07 2013-06-30 13F GREAT LAKES DREDGE + DOCK CO C COM 390607109 86,222 86,222 674 0.0022
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.