DexCom, Inc.
US ˙ NasdaqGS ˙ US2521311074

SecurityDXCM / DexCom, Inc.
InstitutionSei Investments Co
Latest Disclosed Ownership90,204 shares
Latest Disclosed Value $ 5,987,946
Sei Investments Co ownership in DXCM / DexCom, Inc.

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 90,204 shares of DexCom, Inc. (US:DXCM) valued at $5,986,839 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 475,029 shares of DexCom, Inc.. This represents a change in shares of -81.01% during the quarter. The current value of the position is $6,564,145 USD.

Sei Investments Co has a history of taking positions in derivatives of the underlying security (DXCM) 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.

DXCM / DexCom, 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 DEXCOM COM 252131107 90,204 -384,825 -81.01 5,988 -81.27 0.0059
2025-11-13 2025-09-30 13F DEXCOM COM 252131107 475,029 -222,646 -31.91 31,964 -47.51 0.0344
2025-08-14 2025-06-30 13F DEXCOM COM 252131107 697,675 77,767 12.54 60,900 43.86 0.0706
2025-05-14 2025-03-31 13F/A-1 DEXCOM COM 252131107 619,908 137,120 28.40 42,331 12.75 0.0545
2025-05-13 2025-03-31 13F DEXCOM COM 252131107 492,247 9,459 37,980 0.0413
2025-02-11 2024-12-31 13F DEXCOM COM 252131107 482,788 43,391 9.88 37,546 27.46 0.0482
2024-11-12 2024-09-30 13F DEXCOM COM 252131107 439,397 -609,987 -58.13 29,458 -75.24 0.0383
2024-08-13 2024-06-30 13F DEXCOM COM 252131107 1,049,384 -19,447 -1.82 118,978 -19.74 0.1686
2024-05-07 2024-03-31 13F DEXCOM COM 252131107 1,068,831 -424,523 -28.43 148,246 -20.00 0.2172
2024-02-14 2023-12-31 13F DEXCOM COM 252131107 1,493,354 723,709 94.03 185,310 158.07 0.2975
2023-11-14 2023-09-30 13F DEXCOM COM 252131107 769,645 145,528 23.32 71,808 -10.47 0.1290
2023-08-11 2023-06-30 13F DEXCOM COM 252131107 624,117 17,122 2.82 80,205 13.74 0.1399
2023-05-12 2023-03-31 13F DEXCOM COM 252131107 606,995 57,269 10.42 70,520 13.28 0.1310
2023-02-10 2022-12-31 13F DEXCOM COM 252131107 549,726 -77,417 -12.34 62,252 23.25 0.1383
2022-11-14 2022-09-30 13F DEXCOM COM 252131107 627,143 117,373 23.02 50,509 32.76 0.1127
2022-08-15 2022-06-30 13F DEXCOM COM 252131107 509,770 405,922 390.88 38,044 -28.72 0.0822
2022-05-13 2022-03-31 13F DEXCOM COM 252131107 103,848 -77,434 -42.71 53,369 -45.23 0.1073
2022-02-14 2021-12-31 13F DEXCOM COM 252131107 181,282 -82,301 -31.22 97,442 -32.41 0.1828
2021-11-12 2021-09-30 13F DEXCOM COM 252131107 263,583 -25,828 -8.92 144,172 16.65 0.3025
2021-08-06 2021-06-30 13F DEXCOM COM 252131107 289,411 9,270 3.31 123,596 22.84 0.2741
2021-05-12 2021-03-31 13F DEXCOM COM 252131107 280,141 121,508 76.60 100,617 71.84 0.2535
2021-02-08 2020-12-31 13F DEXCOM COM 252131107 158,633 85,046 115.57 58,554 93.28 0.1514
2020-12-04 2020-09-30 13F/A-1 DEXCOM COM 252131107 73,587 -53 -0.07 30,295 1.47 0.0877
2020-11-06 2020-09-30 13F DEXCOM COM 252131107 74,422 782 30,639 73,771.8998
2020-08-17 2020-06-30 13F/A-1 DEXCOM COM 252131107 73,640 -24,682 -25.10 29,857 12.73 0.0927
2020-08-11 2020-06-30 13F DEXCOM COM 252131107 98,248 -74 21,801 59,136.3730
2020-05-14 2020-03-31 13F DEXCOM COM 252131107 98,322 -12,825 -11.54 26,486 8.86 0.0973
2020-02-06 2019-12-31 13F DEXCOM COM 252131107 111,147 94 0.08 24,330 46.80 0.0726
2019-11-12 2019-09-30 13F DEXCOM COM 252131107 111,053 17,935 19.26 16,574 18.60 0.0424
2019-08-14 2019-06-30 13F DEXCOM COM 252131107 93,118 36,408 64.20 13,975 106.79 0.0456
2019-05-15 2019-03-31 13F DEXCOM COM 252131107 56,710 -25,095 -30.68 6,758 -39.57 0.0227
2019-02-13 2018-12-31 13F DEXCOM COM 252131107 81,805 4,786 6.21 11,183 1.54 0.0398
2018-11-08 2018-09-30 13F DEXCOM COM 252131107 77,019 -72,695 -48.56 11,013 -22.54 0.0399
2018-08-03 2018-06-30 13F DEXCOM COM 252131107 149,714 37,905 33.90 14,218 71.47 0.0483
2018-05-11 2018-03-31 13F DEXCOM COM 252131107 111,809 9,011 8.77 8,292 40.54 0.0318
2018-02-08 2017-12-31 13F DEXCOM COM 252131107 102,798 -322,158 -75.81 5,900 -71.62 0.0205
2017-11-06 2017-09-30 13F DEXCOM COM 252131107 424,956 -156,714 -26.94 20,791 -51.14 0.0739
2017-07-31 2017-06-30 13F DEXCOM COM 252131107 581,670 93,498 19.15 42,550 2.87 0.1696
2017-05-05 2017-03-31 13F DEXCOM COM 252131107 488,172 22,597 4.85 41,363 48.81 0.1813
2017-02-02 2016-12-31 13F DEXCOM COM 252131107 465,575 156,085 50.43 27,795 2.45 0.1346
2016-11-04 2016-09-30 13F DEXCOM COM 252131107 309,490 170,984 123.45 27,129 146.90 0.1378
2016-08-11 2016-06-30 13F DEXCOM COM 252131107 138,506 122,944 790.03 10,988 939.55 0.0659
2016-05-10 2016-03-31 13F/A-1 DEXCOM COM 252131107 15,562 -136,600 -89.77 1,057 -91.52 0.0066
2016-02-03 2015-12-31 13F DEXCOM COM 252131107 152,162 -4,762 -3.03 12,462 -7.50 0.0760
2015-11-02 2015-09-30 13F/A-1 DEXCOM COM 252131107 156,924 33,008 26.64 13,472 35.94 0.1237
2015-10-30 2015-09-30 13F DEXCOM COM 252131107 156,924 13,475
2015-08-07 2015-06-30 13F/A-1 DEXCOM COM 252131107 123,916 91,459 281.79 9,910 390.11 0.0896
2015-08-04 2015-06-30 13F DEXCOM COM 252131107 123,916 91,459 9,910 0.0896
2015-05-14 2015-03-31 13F/A-1 DEXCOM COM 252131107 32,457 -2,215 -6.39 2,022 6.14 0.0176
2015-05-01 2015-03-31 13F DEVON ENERGY CORP PUT 252131107 32,457 32,457 2,022 0.0176
2015-02-10 2014-12-31 13F DEXCOM COM 252131107 34,672 34,672 1,905 0.0168
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
(%)
2015-05-01 2015-03-31 13F DEVON ENERGY CORP PUT 32,457 2,022 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.