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

SecurityGLDD / Great Lakes Dredge & Dock Corporation
InstitutionMinerva Advisors LLC
Latest Disclosed Ownership1,029,703 shares
Latest Disclosed Value $ 17,504,951
Minerva Advisors LLC reports 25.91% decrease in ownership of GLDD / Great Lakes Dredge & Dock Corporation

On May 12, 2026 - Minerva Advisors LLC filed a 13F-HR form disclosing ownership of 1,029,703 shares of Great Lakes Dredge & Dock Corporation (US:GLDD) valued at $17,504,951 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 9, 2026 disclosing 1,389,807 shares of Great Lakes Dredge & Dock Corporation. This represents a change in shares of -25.91% during the quarter. The current value of the position is $17,504,951 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 COM 390607109 1,029,703 -360,104 -25.91 17,505 -4.00 8.4346
2026-02-09 2025-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,389,807 0 0.00 18,234 9.43 12.1791
2025-11-12 2025-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,389,807 0 0.00 16,664 -1.56 7.9800
2025-08-13 2025-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,389,807 0 0.00 16,928 40.00 11.0937
2025-05-09 2025-03-31 13F/A-1 GREAT LAKES DREDGE & DOCK COM 390607109 1,389,807 48,000 3.58 12,091 -20.04 8.5940
2025-05-08 2025-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,389,807 48,000 12,091 6.5279
2025-02-04 2024-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,341,807 0 0.00 15,122 7.13 8.8455
2024-11-08 2024-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,341,807 19,470 1.47 14,116 21.72 8.1803
2024-08-12 2024-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,322,337 10,194 0.78 11,597 1.12 7.7322
2024-05-14 2024-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,312,143 36,145 2.83 11,468 17.03 7.0218
2024-02-09 2023-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,275,998 67,700 5.60 9,800 108,777.78 6.1243
2023-11-16 2023-09-30 13F/A-1 GREAT LAKES DREDGE & DOCK COM 390607109 1,208,298 0 0.00 10 -99.91 2.2115
2023-11-16 2023-09-30 13F/A-1 GREAT LAKES DREDGE & DOCK COM 390607109 1,208,298 0 0.00 10 -99.91 2.2115
2023-11-13 2023-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,208,298 0 10 5.4093
2024-01-31 2023-06-30 13F/A-1 GREAT LAKES DREDGE & DOCK COM 390607109 1,208,298 0 0.00 9,836 50.47 6.8061
2023-08-10 2023-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,208,298 0 10 6.7966
2024-01-31 2023-03-31 13F/A-1 GREAT LAKES DREDGE & DOCK COM 390607109 1,208,298 33,000 2.81 6,537 -6.37 4.7151
2023-05-15 2023-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,208,298 33,000 7 4.7151
2024-01-31 2022-12-31 13F/A-1 GREAT LAKES DREDGE & DOCK COM 390607109 1,175,298 168,758 16.77 6,981 -8.49 5.1962
2023-02-13 2022-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,175,298 168,758 7 5.1963
2022-11-10 2022-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,006,540 27,000 2.76 7,629 -40.55 5.7798
2022-08-12 2022-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 979,540 0 0.00 12,832 -6.43 9.2632
2022-05-12 2022-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 979,540 0 0.00 13,714 -10.82 8.8832
2022-02-14 2021-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 979,540 -3,000 -0.31 15,378 3.72 9.2466
2021-11-12 2021-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 982,540 0 0.00 14,827 3.30 8.6209
2021-08-11 2021-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 982,540 -3,000 -0.30 14,354 -0.17 7.5838
2021-05-12 2021-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 985,540 -72,553 -6.86 14,379 3.11 7.8705
2021-02-16 2020-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,058,093 0 0.00 13,945 38.59 7.6729
2020-11-12 2020-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,058,093 -35,649 -3.26 10,062 -0.65 6.7767
2020-08-12 2020-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,093,742 49,873 4.78 10,128 17.32 6.8208
2020-05-14 2020-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,043,869 31,519 3.11 8,633 -24.67 6.7955
2020-02-14 2019-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,012,350 -49,095 -4.63 11,460 3.32 6.1080
2019-11-14 2019-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,061,445 -17,888 -1.66 11,092 -6.66 6.1682
2019-08-01 2019-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,079,333 -32,000 -2.88 11,883 20.14 6.4451
2019-05-15 2019-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,111,333 0 0.00 9,891 34.66 5.5596
2019-02-06 2018-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,111,333 0 0.00 7,345 7.46 4.6947
2018-11-13 2018-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,111,333 0 0.00 6,835 17.14 3.4943
2018-08-01 2018-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,111,333 0 0.00 5,835 15.41 2.9850
2018-05-10 2018-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,111,333 0 0.00 5,056 -15.75 2.6662
2018-02-02 2017-12-31 13F/A-1 GREAT LAKES DREDGE & DOCK COM 390607109 1,111,333 0 0.00 6,001 11.34 3.2423
2018-02-01 2017-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,111,333 0 6,001
2017-11-14 2017-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,111,333 1,949 0.18 5,390 14.32 2.8494
2017-07-31 2017-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,109,384 -1,600 -0.14 4,715 6.10 2.6148
2017-05-11 2017-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,110,984 2,024 0.18 4,444 -4.59 2.3679
2017-02-09 2016-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,108,960 8,800 0.80 4,658 20.96 2.6446
2016-11-14 2016-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,100,160 274,963 33.32 3,851 7.27 2.4117
2016-07-28 2016-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 825,197 0 0.00 3,590 -2.23 2.4355
2016-05-13 2016-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 825,197 31,720 4.00 3,672 16.87 2.4921
2016-02-11 2015-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 793,477 25,000 3.25 3,142 -18.90 2.0776
2015-11-12 2015-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 768,477 90,050 13.27 3,874 -4.37 2.7519
2015-07-30 2015-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 678,427 200,000 41.80 4,051 41.10 2.4773
2015-05-15 2015-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 478,427 3,200 0.67 2,871 -29.42 1.6707
2015-02-09 2014-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 475,227 0 0.00 4,068 38.51 2.2952
2014-10-30 2014-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 475,227 0 0.00 2,937 -22.65 1.8125
2014-07-25 2014-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 475,227 0 0.00 3,797 -12.39 2.1551
2014-05-12 2014-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 475,227 20,000 4.39 4,334 3.61 2.5684
2014-02-10 2013-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 455,227 0 0.00 4,183 23.65 2.4226
2013-11-12 2013-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 455,227 21,620 4.99 3,383 0.15 2.0961
2013-08-02 2013-06-30 13F/A-1 GREAT LAKES DREDGE & DOCK COM 390607109 433,607 433,607 3,378 2.2490
2013-07-31 2013-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 433,607 3,378 2.2546
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.