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

SecurityGLDD / Great Lakes Dredge & Dock Corporation
InstitutionD. E. Shaw & Co., Inc.
ManagerDE Shaw
Latest Disclosed Ownership92,353 shares
Latest Disclosed Value $ 1,570,001
D. E. Shaw & Co., Inc. reports 77.81% decrease in ownership of GLDD / Great Lakes Dredge & Dock Corporation

On May 15, 2026 - D. E. Shaw & Co., Inc. filed a 13F-HR form disclosing ownership of 92,353 shares of Great Lakes Dredge & Dock Corporation (US:GLDD) valued at $1,570,001 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 416,103 shares of Great Lakes Dredge & Dock Corporation. This represents a change in shares of -77.81% during the quarter. The current value of the position is $1,570,001 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)
2026-05-15 2026-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 92,353 -323,750 -77.81 1,570 -71.24 0.0009
2026-02-17 2025-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 416,103 27,222 7.00 5,459 17.10 0.0030
2025-11-14 2025-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 388,881 -49,348 -11.26 4,663 -12.73 0.0026
2025-08-14 2025-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 438,229 -63,527 -12.66 5,342 22.38 0.0038
2025-05-15 2025-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 501,756 -19,361 -3.72 4,365 -25.80 0.0039
2025-02-14 2024-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 521,117 -241,999 -31.71 5,883 -26.78 0.0043
2024-11-14 2024-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 763,116 -60,975 -7.40 8,036 11.06 0.0069
2024-08-14 2024-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 824,091 -6,476 -0.78 7,236 -0.44 0.0068
2024-05-15 2024-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 830,567 -2,532 -0.30 7,267 13.58 0.0062
2024-02-14 2023-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 833,099 45,164 5.73 6,398 1.90 0.0056
2023-11-14 2023-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 787,935 -146,439 -15.67 6,280 -17.64 0.0066
2023-08-14 2023-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 934,374 -304,651 -24.59 7,624 13.33 0.0078
2023-05-15 2023-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,239,025 61,745 5.24 6,728 -3.95 0.0072
2023-02-14 2022-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,177,280 155,154 15.18 7,005 -9.60 0.0077
2022-11-14 2022-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,022,126 -47,996 -4.49 7,748 -44.77 0.0093
2022-08-15 2022-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,070,122 29,428 2.83 14,029 -3.92 0.0164
2022-05-16 2022-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,040,694 -62,257 -5.64 14,601 -15.79 0.0137
2022-02-14 2021-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,102,951 -113,970 -9.37 17,339 -5.58 0.0144
2021-11-15 2021-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,216,921 -36,934 -2.95 18,364 0.25 0.0166
2021-08-16 2021-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,253,855 -234,217 -15.74 18,319 -15.57 0.0158
2021-05-17 2021-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,488,072 54,236 3.78 21,696 14.90 0.0209
2021-02-16 2020-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,433,836 -138,326 -8.80 18,883 26.29 0.0169
2020-11-16 2020-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,572,162 161,329 11.44 14,952 14.44 0.0153
2020-08-14 2020-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,410,833 53,267 3.92 13,065 15.96 0.0156
2020-05-15 2020-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,357,566 110,692 8.88 11,267 -20.24 0.0176
2020-02-14 2019-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,246,874 -257,880 -17.14 14,127 -10.16 0.0162
2019-11-14 2019-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,504,754 15,705 1.05 15,725 -4.34 0.0194
2019-08-14 2019-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,489,049 279,745 23.13 16,439 52.57 0.0205
2019-05-15 2019-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 1,209,304 248,035 25.80 10,775 69.31 0.0139
2019-02-14 2018-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 961,269 94,998 10.97 6,364 18.49 0.0088
2018-11-14 2018-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 866,271 -26,767 -3.00 5,371 14.57 0.0065
2018-08-14 2018-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 893,038 16,654 1.90 4,688 16.30 0.0061
2018-05-15 2018-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 876,384 44,932 5.40 4,031 -10.20 0.0055
2018-02-14 2017-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 831,452 30,996 3.87 4,489 15.64 0.0062
2017-11-14 2017-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 800,456 28,004 3.63 3,882 16.86 0.0060
2017-08-14 2017-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 772,452 79,236 11.43 3,322 19.80 0.0055
2017-05-15 2017-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 693,216 41,418 6.35 2,773 1.32 0.0049
2017-02-14 2016-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 651,798 110,679 20.45 2,737 44.59 0.0046
2016-11-14 2016-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 541,119 69,709 14.79 1,893 -7.88 0.0033
2016-08-15 2016-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 471,410 21,374 4.75 2,055 2.39 0.0038
2016-05-16 2016-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 450,036 15,813 3.64 2,007 16.69 0.0036
2016-02-16 2015-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 434,223 114,368 35.76 1,720 6.70 0.0026
2015-11-16 2015-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 319,855 226,695 243.34 1,612 190.45 0.0024
2015-08-14 2015-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 93,160 73,392 371.27 555 366.39 0.0008
2015-05-15 2015-03-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 19,768 -77,853 -79.75 119 -85.77 0.0002
2015-02-17 2014-12-31 13F GREAT LAKES DREDGE & DOCK COM 390607109 97,621 24,099 32.78 836 84.14 0.0011
2014-11-14 2014-09-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 73,522 73,522 42.99 454 12.94 0.0006
2013-11-20 2013-09-30 13F/A-1 GREAT LAKES DREDGE & DOCK COM 390607109 0 -51,416 -100.00 0 -100.00
2013-08-14 2013-06-30 13F GREAT LAKES DREDGE & DOCK COM 390607109 51,416 51,416 402 0.0008
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.