Anterix Inc.
US ˙ NasdaqCM ˙ US03676C1009

SecurityATEX / Anterix Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership161,163 shares
Latest Disclosed Value $ 6,154,815
Citadel Advisors Llc ownership in ATEX / Anterix Inc.

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 161,163 shares of Anterix Inc. (US:ATEX) valued at $6,154,815 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 108,380 shares of Anterix Inc.. This represents a change in shares of 48.70% during the quarter. The current value of the position is $10,785,028 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (ATEX) in the form of stock options. The firm currently holds call options representing 47,100 of underlying shares valued at $1,798,749 USD and put options representing 16,400 of underlying shares valued at $626,316 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

ATEX / Anterix Inc. Historical Put/Call Ratio
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 ANTERIX COM 03676C100 161,163 52,783 48.70 6,155 160.21 0.0009
2026-02-17 2025-12-31 13F ANTERIX COM 03676C100 108,380 -2,714 -2.44 2,366 -0.84 0.0004
2025-11-14 2025-09-30 13F ANTERIX COM 03676C100 111,094 -161,695 -59.27 2,385 -65.91 0.0004
2025-08-14 2025-06-30 13F ANTERIX COM 03676C100 272,789 23,595 9.47 6,997 -23.28 0.0012
2025-05-15 2025-03-31 13F ANTERIX COM 03676C100 249,194 81,291 48.42 9,120 77.12 0.0017
2025-02-14 2024-12-31 13F ANTERIX COM 03676C100 167,903 -31,711 -15.89 5,150 -31.50 0.0009
2024-11-14 2024-09-30 13F ANTERIX COM 03676C100 199,614 32,093 19.16 7,517 13.34 0.0015
2024-08-14 2024-06-30 13F ANTERIX COM 03676C100 167,521 98,866 144.00 6,632 187.47 0.0013
2024-05-15 2024-03-31 13F ANTERIX COM 03676C100 68,655 -12,655 -15.56 2,307 -14.84 0.0004
2024-02-14 2023-12-31 13F ANTERIX COM 03676C100 81,310 706 0.88 2,709 7.12 0.0005
2023-11-14 2023-09-30 13F ANTERIX COM 03676C100 80,604 5,811 7.77 2,529 6.71 0.0005
2023-08-14 2023-06-30 13F ANTERIX COM 03676C100 74,793 26,331 54.33 2,370 48.03 0.0005
2023-05-15 2023-03-31 13F ANTERIX COM 03676C100 48,462 40,283 492.52 1,601 508.75 0.0004
2023-02-14 2022-12-31 13F ANTERIX COM 03676C100 8,179 -46,366 -85.01 263 -86.50 0.0001
2022-11-14 2022-09-30 13F ANTERIX COM 03676C100 54,545 54,545 1,948 0.0004
2022-05-16 2022-03-31 13F ANTERIX COM 03676C100 0 -12,684 -100.00 0 -100.00
2022-02-14 2021-12-31 13F ANTERIX COM 03676C100 12,684 184 1.47 745 -1.84 0.0002
2021-11-15 2021-09-30 13F ANTERIX Cmn 03676C100 12,500 4,912 64.73 759 66.81 0.0002
2021-08-16 2021-06-30 13F ANTERIX COM 03676C100 7,588 -23,731 -75.77 455 -69.19 0.0001
2021-05-21 2021-03-31 13F/A-1 ANTERIX COM 03676C100 31,319 6,721 27.32 1,477 59.68 0.0004
2021-05-17 2021-03-31 13F ANTERIX COM 03676C100 31,319 6,721 1,477 0.0004
2021-02-16 2020-12-31 13F ANTERIX COM 03676C100 24,598 8,356 51.45 925 74.20 0.0002
2020-11-16 2020-09-30 13F ANTERIX COM 03676C100 16,242 -46,864 -74.26 531 -81.44 0.0002
2020-08-14 2020-06-30 13F ANTERIX Cmn 03676C100 63,106 18,313 40.88 2,861 39.83 0.0010
2020-05-15 2020-03-31 13F ANTERIX Cmn 03676C100 44,793 38,276 587.33 2,046 568.63 0.0009
2019-08-14 2019-06-30 13F PDVWIRELESS Cmn 69290R104 6,517 -4,105 -38.65 306 -17.96 0.0001
2019-05-15 2019-03-31 13F PDVWIRELESS Cmn 69290R104 10,622 -3,540 -25.00 373 -29.62 0.0002
2019-02-14 2018-12-31 13F PDVWIRELESS Cmn 69290R104 14,162 14,162 530 0.0003
2018-11-13 2018-09-30 13F PDVWIRELESS Cmn 69290R104 0 -14,649 -100.00 0 -100.00
2018-08-14 2018-06-30 13F/A-1 PDVWIRELESS Cmn 69290R104 14,649 14,649 366 0.0002
2018-08-10 2018-06-30 13F PDVWIRELESS Cmn 69290R104 14,649 366 0.0002
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F ANTERIX COM Call 47,100 1,799 n/a n/a n/a
2025-11-14 2025-09-30 13F ANTERIX COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-08-14 2025-06-30 13F ANTERIX COM Call 14,800 30.97 380 -8.23 n/a n/a n/a
2025-05-15 2025-03-31 13F ANTERIX COM Call 11,300 -12.40 414 4.56 n/a n/a n/a
2025-02-14 2024-12-31 13F ANTERIX COM Call 12,900 32.99 396 8.22 n/a n/a n/a
2024-11-14 2024-09-30 13F ANTERIX COM Call 9,700 -27.07 365 -30.61 n/a n/a n/a
2024-08-14 2024-06-30 13F ANTERIX COM Call 13,300 29.13 527 52.02 n/a n/a n/a
2024-05-15 2024-03-31 13F ANTERIX COM Call 10,300 -52.97 346 -52.54 n/a n/a n/a
2024-02-14 2023-12-31 13F ANTERIX COM Call 21,900 -57.88 730 -55.30 n/a n/a n/a
2023-11-14 2023-09-30 13F ANTERIX COM Call 52,000 195.45 1,632 192.82 n/a n/a n/a
2023-08-14 2023-06-30 13F ANTERIX COM Call 17,600 -18.14 558 -21.55 n/a n/a n/a
2023-05-15 2023-03-31 13F ANTERIX COM Call 21,500 -39.44 710 -37.83 n/a n/a n/a
2023-02-14 2022-12-31 13F ANTERIX COM Call 35,500 93.99 1,142 74.62 n/a n/a n/a
2022-11-14 2022-09-30 13F ANTERIX COM Call 18,300 654 n/a n/a n/a
2022-08-15 2022-06-30 13F ANTERIX COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-05-16 2022-03-31 13F ANTERIX COM Call 5,200 6.12 301 4.51 n/a n/a n/a
2022-02-14 2021-12-31 13F ANTERIX COM Call 4,900 -30.00 288 -32.24 n/a n/a n/a
2021-11-15 2021-09-30 13F ANTERIX Cmn Call 7,000 -87.06 425 -86.90 n/a n/a n/a
2021-08-16 2021-06-30 13F ANTERIX COM Call 54,100 -42.51 3,245 -26.88 n/a n/a n/a
2021-05-21 2021-03-31 13F/A ANTERIX COM Call 94,100 52.02 4,438 90.72 n/a n/a n/a
2021-05-17 2021-03-31 13F ANTERIX COM Call 94,100 4,438 n/a n/a n/a
2021-02-16 2020-12-31 13F ANTERIX COM Call 61,900 -66.45 2,327 -61.44 n/a n/a n/a
2020-11-16 2020-09-30 13F ANTERIX COM Call 184,500 241.67 6,035 146.53 n/a n/a n/a
2020-08-14 2020-06-30 13F ANTERIX Cmn Call 54,000 500.00 2,448 495.62 n/a n/a n/a
2020-05-15 2020-03-31 13F ANTERIX Cmn Call 9,000 411 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F ANTERIX COM Put 16,400 36.67 626 139.85 n/a n/a n/a
2026-02-17 2025-12-31 13F ANTERIX COM Put 12,000 262 n/a n/a n/a
2025-11-14 2025-09-30 13F ANTERIX COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-08-14 2025-06-30 13F ANTERIX COM Put 13,700 52.22 351 6.69 n/a n/a n/a
2025-05-15 2025-03-31 13F ANTERIX COM Put 9,000 125.00 329 169.67 n/a n/a n/a
2025-02-14 2024-12-31 13F ANTERIX COM Put 4,000 60.00 123 29.79 n/a n/a n/a
2024-11-14 2024-09-30 13F ANTERIX COM Put 2,500 -82.01 94 -82.91 n/a n/a n/a
2024-08-14 2024-06-30 13F ANTERIX COM Put 13,900 434.62 550 532.18 n/a n/a n/a
2024-05-15 2024-03-31 13F ANTERIX COM Put 2,600 -18.75 87 -17.92 n/a n/a n/a
2024-02-14 2023-12-31 13F ANTERIX COM Put 3,200 -87.15 107 -86.43 n/a n/a n/a
2023-11-14 2023-09-30 13F ANTERIX COM Put 24,900 100.81 781 99.23 n/a n/a n/a
2023-08-14 2023-06-30 13F ANTERIX COM Put 12,400 588.89 393 564.41 n/a n/a n/a
2023-05-15 2023-03-31 13F ANTERIX COM Put 1,800 -52.63 59 -51.64 n/a n/a n/a
2023-02-14 2022-12-31 13F ANTERIX COM Put 3,800 122 n/a n/a n/a
2022-05-16 2022-03-31 13F ANTERIX COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-02-14 2021-12-31 13F ANTERIX COM Put 6,600 -37.74 388 -39.66 n/a n/a n/a
2021-11-15 2021-09-30 13F ANTERIX Cmn Put 10,600 -68.26 643 -67.91 n/a n/a n/a
2021-08-16 2021-06-30 13F ANTERIX COM Put 33,400 -6.18 2,004 19.36 n/a n/a n/a
2021-05-21 2021-03-31 13F/A ANTERIX COM Put 35,600 182.54 1,679 254.22 n/a n/a n/a
2021-05-17 2021-03-31 13F ANTERIX COM Put 35,600 1,679 n/a n/a n/a
2021-02-16 2020-12-31 13F ANTERIX COM Put 12,600 -5.97 474 8.22 n/a n/a n/a
2020-11-16 2020-09-30 13F ANTERIX COM Put 13,400 88.73 438 36.02 n/a n/a n/a
2020-08-14 2020-06-30 13F ANTERIX Cmn Put 7,100 -46.21 322 -46.60 n/a n/a n/a
2020-05-15 2020-03-31 13F ANTERIX Cmn Put 13,200 603 n/a n/a n/a
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.