T-Mobile US, Inc.
MX ˙ BMV ˙ US8725901040
SecurityMX:TMUS / T-Mobile US, Inc.
InstitutionSei Investments Co
Latest Disclosed Ownership164,736 shares
Latest Disclosed Value $ 33,448,934
Sei Investments Co ownership in TMUS / T-Mobile US, Inc.

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 164,736 shares of T-Mobile US, Inc. (MX:TMUS) valued at $33,448,934 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 169,149 shares of T-Mobile US, Inc.. This represents a change in shares of -2.61% during the quarter.

Sei Investments Co has a history of taking positions in derivatives of the underlying security (TMUS) in the form of stock options.

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.

MX:TMUS / T-Mobile US, 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)
2026-02-13 2025-12-31 13F T-MOBILE US COM 872590104 164,736 -4,413 -2.61 33,449 -17.40 0.0330
2025-11-13 2025-09-30 13F T-MOBILE US COM 872590104 169,149 26,562 18.63 40,494 19.20 0.0435
2025-08-14 2025-06-30 13F T-MOBILE US COM 872590104 142,587 12,794 9.86 33,972 -1.86 0.0394
2025-05-14 2025-03-31 13F/A-1 T-MOBILE US COM 872590104 129,793 -7,456 -5.43 34,617 14.27 0.0446
2025-05-13 2025-03-31 13F T-MOBILE US COM 872590104 134,096 -3,153 31,696 0.0345
2025-02-11 2024-12-31 13F T-MOBILE US COM 872590104 137,249 -12,940 -8.62 30,294 -2.26 0.0389
2024-11-12 2024-09-30 13F T-MOBILE US COM 872590104 150,189 -6,592 -4.20 30,993 12.21 0.0402
2024-08-13 2024-06-30 13F T-MOBILE US COM 872590104 156,781 -9,729 -5.84 27,622 1.63 0.0391
2024-05-07 2024-03-31 13F T-MOBILE US COM 872590104 166,510 -17,968 -9.74 27,178 -8.10 0.0398
2024-02-14 2023-12-31 13F T-MOBILE US COM 872590104 184,478 5,552 3.10 29,574 18.02 0.0475
2023-11-14 2023-09-30 13F T-MOBILE US COM 872590104 178,926 -18,117 -9.19 25,057 -8.45 0.0450
2023-08-11 2023-06-30 13F T-MOBILE US COM 872590104 197,043 -103,756 -34.49 27,369 -37.18 0.0477
2023-05-12 2023-03-31 13F T-MOBILE US COM 872590104 300,799 20,573 7.34 43,566 11.05 0.0809
2023-02-10 2022-12-31 13F T-MOBILE US COM 872590104 280,226 13,714 5.15 39,232 9.71 0.0872
2022-11-14 2022-09-30 13F T-MOBILE US COM 872590104 266,512 34,061 14.65 35,758 14.28 0.0798
2022-08-15 2022-06-30 13F T-MOBILE US COM 872590104 232,451 1,853 0.80 31,290 5.70 0.0676
2022-05-13 2022-03-31 13F T-MOBILE US COM 872590104 230,598 77,518 50.64 29,603 66.66 0.0595
2022-02-14 2021-12-31 13F T-MOBILE US COM 872590104 153,080 11,722 8.29 17,763 -2.41 0.0333
2021-11-12 2021-09-30 13F T-MOBILE US COM 872590104 141,358 -6,652 -4.49 18,202 -15.23 0.0382
2021-08-06 2021-06-30 13F T-MOBILE US COM 872590104 148,010 25,695 21.01 21,472 38.25 0.0476
2021-05-12 2021-03-31 13F T-MOBILE US COM 872590104 122,315 -75,418 -38.14 15,531 -41.80 0.0391
2021-02-08 2020-12-31 13F T-MOBILE US COM 872590104 197,733 -41,895 -17.48 26,684 -2.63 0.0690
2020-12-04 2020-09-30 13F/A-1 T-MOBILE US COM 872590104 239,628 22,087 10.15 27,405 20.95 0.0794
2020-11-06 2020-09-30 13F T-MOBILE US COM 872590104 241,801 24,260 27,654 66,584.6834
2020-08-17 2020-06-30 13F/A-1 T-MOBILE US COM 872590104 217,541 89,433 69.81 22,658 110.79 0.0703
2020-08-11 2020-06-30 13F T-MOBILE US COM 872590104 96,330 -31,778 7,644 20,734.7569
2020-05-14 2020-03-31 13F T MOBILE US COM 872590104 128,108 34,171 36.38 10,749 45.93 0.0395
2020-02-06 2019-12-31 13F T MOBILE US COM 872590104 93,937 7,232 8.34 7,366 7.97 0.0220
2019-11-12 2019-09-30 13F T MOBILE US COM 872590104 86,705 9,115 11.75 6,822 19.33 0.0175
2019-08-14 2019-06-30 13F T MOBILE US COM 872590104 77,590 -19,793 -20.32 5,717 -14.87 0.0187
2019-05-15 2019-03-31 13F T MOBILE US COM 872590104 97,383 9,144 10.36 6,716 8.80 0.0226
2019-02-13 2018-12-31 13F T MOBILE US COM 872590104 88,239 500 0.57 6,173 0.24 0.0220
2018-11-08 2018-09-30 13F T MOBILE US COM 872590104 87,739 15,253 21.04 6,158 42.18 0.0223
2018-08-03 2018-06-30 13F T MOBILE US COM 872590104 72,486 -190,645 -72.45 4,331 -73.04 0.0147
2018-05-11 2018-03-31 13F T MOBILE US COM 872590104 263,131 165,222 168.75 16,062 158.27 0.0616
2018-02-08 2017-12-31 13F T MOBILE US COM 872590104 97,909 1,839 1.91 6,219 4.98 0.0216
2017-11-06 2017-09-30 13F T MOBILE US COM 872590104 96,070 -4,015 -4.01 5,924 -2.36 0.0211
2017-07-31 2017-06-30 13F T MOBILE US COM 872590104 100,085 -9,493 -8.66 6,067 -14.27 0.0242
2017-05-05 2017-03-31 13F T MOBILE US COM 872590104 109,578 2,216 2.06 7,077 14.63 0.0310
2017-02-02 2016-12-31 13F T MOBILE US COM 872590104 107,362 -28,814 -21.16 6,174 -2.96 0.0299
2016-11-04 2016-09-30 13F T MOBILE US COM 872590104 136,176 -164,551 -54.72 6,362 -51.11 0.0323
2016-08-11 2016-06-30 13F T MOBILE US COM 872590104 300,727 3,777 1.27 13,013 14.41 0.0780
2016-05-10 2016-03-31 13F/A-1 T MOBILE US COM 872590104 296,950 -14,457 -4.64 11,374 -6.63 0.0708
2016-02-03 2015-12-31 13F T MOBILE US COM 872590104 311,407 112,314 56.41 12,182 53.70 0.0742
2015-11-02 2015-09-30 13F/A-1 T MOBILE US COM 872590104 199,093 -31 -0.02 7,926 2.67 0.0728
2015-10-30 2015-09-30 13F T MOBILE US COM 872590104 199,093 7,927
2015-08-07 2015-06-30 13F/A-1 TICC CAPITAL PUT 872590104 0 -1,206 -100.00 0 -100.00
2015-08-07 2015-06-30 13F/A-1 T MOBILE US COM 872590104 199,124 197,918 16,411.11 7,720 20,764.86 0.0698
2015-08-04 2015-06-30 13F T MOBILE US COM 872590104 199,124 197,918 7,720 0.0698
2015-05-14 2015-03-31 13F/A-1 T MOBILE US COM 872590104 1,206 173 16.75 37 32.14 0.0003
2015-05-01 2015-03-31 13F TICC CAPITAL PUT 872590104 1,206 1,206 37 0.0003
2015-02-10 2014-12-31 13F T MOBILE US COM 872590104 1,033 1,033 28 0.0002
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
(%)
2015-08-07 2015-06-30 13F/A TICC CAPITAL PUT 0 -100.00 0 -100.00 n/a n/a n/a
2015-05-01 2015-03-31 13F TICC CAPITAL PUT 1,206 37 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.