Antero Midstream Corporation
US ˙ NYSE ˙ US03676B1026

SecurityAM / Antero Midstream Corporation
InstitutionOppenheimer & Co Inc
Latest Disclosed Ownership25,630 shares
Latest Disclosed Value $ 584,364
Oppenheimer & Co Inc reports 82.91% decrease in ownership of AM / Antero Midstream Corporation

On April 23, 2026 - Oppenheimer & Co Inc filed a 13F-HR form disclosing ownership of 25,630 shares of Antero Midstream Corporation (US:AM) valued at $584,364 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 2, 2026 disclosing 150,012 shares of Antero Midstream Corporation. This represents a change in shares of -82.91% during the quarter. The current value of the position is $545,150 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)
2026-04-23 2026-03-31 13F ANTERO MIDSTREAM COM 03676B102 25,630 -124,382 -82.91 584 -78.11 0.0071
2026-02-02 2025-12-31 13F ANTERO MIDSTREAM COM 03676B102 150,012 -354,743 -70.28 2,669 -72.81 0.0379
2025-11-06 2025-09-30 13F ANTERO MIDSTREAM COM 03676B102 504,755 146,300 40.81 9,812 44.46 0.1197
2025-07-31 2025-06-30 13F ANTERO MIDSTREAM COM 03676B102 358,455 -383,802 -51.71 6,793 -49.16 0.0898
2025-04-23 2025-03-31 13F ANTERO MIDSTREAM COM 03676B102 742,257 48,261 6.95 13,361 27.58 0.2017
2025-02-05 2024-12-31 13F ANTERO MIDSTREAM COM 03676B102 693,996 7,063 1.03 10,472 1.30 0.1563
2024-11-05 2024-09-30 13F ANTERO MIDSTREAM COM 03676B102 686,933 293,238 74.48 10,338 78.15 0.1577
2024-08-08 2024-06-30 13F ANTERO MIDSTREAM COM 03676B102 393,695 -143,594 -26.73 5,803 -23.18 0.0921
2024-05-07 2024-03-31 13F ANTERO MIDSTREAM COM 03676B102 537,289 110,982 26.03 7,554 41.43 0.1253
2024-02-13 2023-12-31 13F ANTERO MIDSTREAM COM 03676B102 426,307 201,572 89.69 5,342 98.40 0.0982
2023-11-08 2023-09-30 13F ANTERO MIDSTREAM COM 03676B102 224,735 -114,066 -33.67 2,692 -31.50 0.0556
2023-08-03 2023-06-30 13F ANTERO MIDSTREAM COM 03676B102 338,801 -242,770 -41.74 3,930 -35.57 0.0786
2023-05-10 2023-03-31 13F ANTERO MIDSTREAM COM 03676B102 581,571 -78,255 -11.86 6,101 -14.31 0.1294
2023-02-08 2022-12-31 13F ANTERO MIDSTREAM COM 03676B102 659,826 164,477 33.20 7,120 56.56 0.1621
2022-11-14 2022-09-30 13F ANTERO MIDSTREAM COM 03676B102 495,349 -27,072 -5.18 4,547 -3.83 0.1064
2022-08-08 2022-06-30 13F ANTERO MIDSTREAM COM 03676B102 522,421 16,770 3.32 4,728 -13.99 0.1018
2022-05-12 2022-03-31 13F ANTERO MIDSTREAM COM 03676B102 505,651 89,475 21.50 5,497 36.44 0.0991
2022-02-02 2021-12-31 13F ANTERO MIDSTREAM COM 03676B102 416,176 -59,563 -12.52 4,029 -18.72 0.0704
2021-11-12 2021-09-30 13F ANTERO MIDSTREAM COM 03676B102 475,739 69,193 17.02 4,957 17.35 0.0928
2021-08-03 2021-06-30 13F ANTERO MIDSTREAM COM 03676B102 406,546 11,326 2.87 4,224 18.35 0.0757
2021-05-10 2021-03-31 13F ANTERO MIDSTREAM COM 03676B102 395,220 212,337 116.11 3,569 153.12 0.0712
2021-02-11 2020-12-31 13F ANTERO MIDSTREAM COM 03676B102 182,883 52,111 39.85 1,410 100.85 0.0298
2020-11-13 2020-09-30 13F ANTERO MIDSTREAM COM 03676B102 130,772 50,472 62.85 702 71.64 0.0176
2020-08-11 2020-06-30 13F ANTERO MIDSTREAM COM 03676B102 80,300 46,396 136.85 409 476.06 0.0106
2020-05-08 2020-03-31 13F ANTERO MIDSTREAM COM 03676B102 33,904 -7,550 -18.21 71 -77.46 0.0022
2020-02-07 2019-12-31 13F ANTERO MIDSTREAM COM 03676B102 41,454 -29,804 -41.83 315 -40.23 0.0078
2019-10-31 2019-09-30 13F ANTERO MIDSTREAM COM 03676B102 71,258 3,447 5.08 527 -32.18 0.0144
2019-08-09 2019-06-30 13F ANTERO MIDSTREAM COM 03676B102 67,811 67,811 777 0.0211
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.