Middlesex Water Company
US ˙ NasdaqGS ˙ US5966801087

SecurityMSEX / Middlesex Water Company
InstitutionFirst Manhattan Co
Latest Disclosed Ownership143,889 shares
Latest Disclosed Value $ 7,489,422
First Manhattan Co reports 2.27% decrease in ownership of MSEX / Middlesex Water Company

On May 15, 2026 - First Manhattan Co filed a 13F-HR form disclosing ownership of 143,889 shares of Middlesex Water Company (US:MSEX) valued at $7,489,422 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 147,228 shares of Middlesex Water Company. This represents a change in shares of -2.27% during the quarter. The current value of the position is $7,679,356 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 MIDDLESEX WTR COM 596680108 143,889 -3,339 -2.27 7,489 0.89 0.0208
2026-02-17 2025-12-31 13F MIDDLESEX WTR COM 596680108 147,228 -125 -0.08 7,423 -6.91 0.0195
2025-11-14 2025-09-30 13F MIDDLESEX WTR COM 596680108 147,353 -11,800 -7.41 7,975 -7.52 0.0211
2025-08-14 2025-06-30 13F MIDDLESEX WTR COM 596680108 159,153 -10,635 -6.26 8,623 -20.78 0.0243
2025-05-15 2025-03-31 13F MIDDLESEX WTR COM 596680108 169,788 -8,387 -4.71 10,883 15.24 0.0318
2025-02-14 2024-12-31 13F MIDDLESEX WTR COM 596680108 178,175 -8,448 -4.53 9,445 -22.43 0.0277
2024-11-14 2024-09-30 13F MIDDLESEX WTR COM 596680108 186,623 -1,135 -0.60 12,175 24.08 0.0361
2024-08-15 2024-06-30 13F/A-1 MIDDLESEX WTR COM 596680108 187,758 -5,130 -2.66 9,812 -3.10 0.0315
2024-08-14 2024-06-30 13F MIDDLESEX WTR COM 596680108 187,758 -5,130 9,812 0.0315
2024-05-15 2024-03-31 13F MIDDLESEX WTR COM 596680108 192,888 -100 -0.05 10,127 -20.03 0.0328
2024-02-13 2023-12-31 13F MIDDLESEX WTR COM 596680108 192,988 3,267 1.72 12,664 0.75 0.0439
2023-11-14 2023-09-30 13F MIDDLESEX WTR COM 596680108 189,721 18,100 10.55 12,569 -9.20 0.0464
2023-08-14 2023-06-30 13F MIDDLESEX WTR COM 596680108 171,621 -23,634 -12.10 13,843 -9.25 0.0507
2023-05-15 2023-03-31 13F MIDDLESEX WTR COM 596680108 195,255 -27,985 -12.54 15,253 -13.15 0.0585
2023-02-14 2022-12-31 13F MIDDLESEX WTR COM 596680108 223,240 375 0.17 17,562 2.07 0.0644
2022-11-14 2022-09-30 13F MIDDLESEX WTR COM 596680108 222,865 -3,400 -1.50 17,205 -13.27 0.0729
2022-08-15 2022-06-30 13F MIDDLESEX WTR COM 596680108 226,265 2,530 1.13 19,838 -15.69 0.0800
2022-05-16 2022-03-31 13F MIDDLESEX WTR COM 596680108 223,735 4,700 2.15 23,530 -10.70 0.0770
2022-02-14 2021-12-31 13F MIDDLESEX WTR COM 596680108 219,035 20,170 10.14 26,349 28.92 0.0868
2021-11-15 2021-09-30 13F MIDDLESEX WTR COM 596680108 198,865 -2,099 -1.04 20,439 24.45 0.0753
2021-08-16 2021-06-30 13F MIDDLESEX WTR COM 596680108 200,964 -3,814 -1.86 16,424 1.50 0.0600
2021-05-14 2021-03-31 13F MIDDLESEX WTR COM 596680108 204,778 -1,455 -0.71 16,181 8.27 0.0697
2021-02-16 2020-12-31 13F MIDDLESEX WTR COM 596680108 206,233 -13,831 -6.28 14,945 9.28 0.0715
2020-11-12 2020-09-30 13F MIDDLESEX WATER COMMON 596680108 220,064 -1,008 -0.46 13,676 -7.91 0.0705
2020-08-14 2020-06-30 13F MIDDLESEX WATER COMMON 596680108 221,072 -43,010 -16.29 14,851 -6.46 0.0858
2020-05-06 2020-03-31 13F MIDDLESEX WATER COMMON 596680108 264,082 -9,517 -3.48 15,876 -8.72 0.1029
2020-02-13 2019-12-31 13F MIDDLESEX WATER COMMON 596680108 273,599 -12,488 -4.37 17,392 -6.41 0.0873
2019-11-13 2019-09-30 13F MIDDLESEX WATER COMMON 596680108 286,087 -8,304 -2.82 18,584 6.55 0.1024
2019-08-16 2019-06-30 13F MIDDLESEX WATER COMMON 596680108 294,391 -5,541 -1.85 17,442 3.86 0.0968
2019-04-12 2019-03-31 13F MIDDLESEX WATER COMMON 596680108 299,932 -9,744 -3.15 16,793 1.65 0.0969
2019-01-30 2018-12-31 13F MIDDLESEX WATER COMMON 596680108 309,676 -4,675 -1.49 16,521 8.55 0.1028
2018-10-15 2018-09-30 13F MIDDLESEX WATER COMMON 596680108 314,351 -8,446 -2.62 15,220 11.81 0.0811
2018-08-01 2018-06-30 13F MIDDLESEX WATER COMMON 596680108 322,797 1,200 0.37 13,612 15.34 0.0785
2018-04-20 2018-03-31 13F MIDDLESEX WATER COMMON 596680108 321,597 -4,016 -1.23 11,802 -9.18 0.0671
2018-01-22 2017-12-31 13F MIDDLESEX WATER COMMON 596680108 325,613 -9,284 -2.77 12,995 -1.19 0.0712
2017-10-25 2017-09-30 13F MIDDLESEX WATER COMMON 596680108 334,897 -4,000 -1.18 13,151 -2.00 0.0753
2017-08-10 2017-06-30 13F/A-2 MIDDLESEX WATER COMMON 596680108 338,897 16,800 5.22 13,420 12.76 0.0783
2017-08-01 2017-06-30 13F/A-1 MIDDLESEX WATER COMMON 596680108 338,897 0 13,420 0.0783
2017-07-28 2017-06-30 13F MIDDLESEX WATER COMMON 596680108 338,897 16,800 13,420
2017-04-25 2017-03-31 13F/A-1 MIDDLESEX WATER COMMON 596680108 322,097 -2,500 -0.77 11,901 -14.61 0.0707
2017-04-24 2017-03-31 13F MIDDLESEX WATER COMMON 596680108 331,997 11,699
2017-01-25 2016-12-31 13F MIDDLESEX WATER COMMON 596680108 324,597 -7,400 -2.23 13,938 19.14 0.0848
2016-10-20 2016-09-30 13F MIDDLESEX WATER COMMON 596680108 331,997 -12,280 -3.57 11,699 -21.66 0.0714
2016-07-14 2016-06-30 13F MIDDLESEX WATER COMMON 596680108 344,277 -6,633 -1.89 14,934 37.96 0.0917
2016-04-22 2016-03-31 13F MIDDLESEX WATER COMMON 596680108 350,910 3,000 0.86 10,825 17.24 0.0666
2016-01-20 2015-12-31 13F MIDDLESEX WATER COMMON 596680108 347,910 -6,600 -1.86 9,233 9.25 0.0567
2015-10-26 2015-09-30 13F MIDDLESEX WATER COMMON 596680108 354,510 1,500 0.42 8,451 6.13 0.0543
2015-07-17 2015-06-30 13F MIDDLESEX WATER COMMON 596680108 353,010 1,517 0.43 7,963 -0.45 0.0470
2015-04-30 2015-03-31 13F MIDDLESEX WATER COMMON 596680108 351,493 -2,650 -0.75 7,999 -2.05 0.0461
2015-01-20 2014-12-31 13F MIDDLESEX WATER COMMON 596680108 354,143 1,200 0.34 8,166 18.06 0.0462
2014-10-23 2014-09-30 13F MIDDLESEX WATER COMMON 596680108 352,943 400 0.11 6,917 -7.35 0.0402
2014-08-14 2014-06-30 13F/A-1 MIDDLESEX WATER COMMON 596680108 352,543 19,350 5.81 7,466 2.70 0.0473
2014-05-16 2014-03-31 13F MIDDLESEX WATER COMMON 596680108 333,193 1,634 0.49 7,270 4.72 0.0479
2014-02-04 2013-12-31 13F MIDDLESEX WATER COMMON 596680108 331,559 1,000 0.30 6,942 -1.81 0.0459
2013-10-29 2013-09-30 13F MIDDLESEX WATER COMMON 596680108 330,559 -1,500 -0.45 7,070 0.63 0.0494
2013-08-13 2013-06-30 13F MIDDLESEX WATER COMMON 596680108 332,059 332,059 7,026 0.0483
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.