DexCom, Inc.
MX ˙ BMV ˙ US2521311074
SecurityMX:DXCM / DexCom, Inc.
InstitutionBamco Inc /ny/
Latest Disclosed Ownership241,000 shares
Latest Disclosed Value $ 15,134,800
Bamco Inc /ny/ reports 6.41% decrease in ownership of DXCM / DexCom, Inc.

On May 15, 2026 - Bamco Inc /ny/ filed a 13F-HR form disclosing ownership of 241,000 shares of DexCom, Inc. (MX:DXCM) valued at $15,134,800 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 257,500 shares of DexCom, Inc.. This represents a change in shares of -6.41% during the quarter.

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 DEXCOM COM 252131107 241,000 -16,500 -6.41 15,135 -11.45 0.0457
2026-02-17 2025-12-31 13F DEXCOM COM 252131107 257,500 -15,000 -5.50 17,090 -6.80 0.0463
2025-11-14 2025-09-30 13F DEXCOM COM 252131107 272,500 -60,000 -18.05 18,337 -36.82 0.0486
2025-08-14 2025-06-30 13F DEXCOM COM 252131107 332,500 -100,000 -23.12 29,024 -1.73 0.0787
2025-05-15 2025-03-31 13F DEXCOM COM 252131107 432,500 0 0.00 29,535 -12.19 0.0868
2025-02-14 2024-12-31 13F DEXCOM COM 252131107 432,500 -132,354 -23.43 33,636 -11.18 0.0869
2024-11-14 2024-09-30 13F DEXCOM COM 252131107 564,854 -401,618 -41.56 37,868 -65.44 0.1005
2024-08-14 2024-06-30 13F DEXCOM COM 252131107 966,472 -1,511 -0.16 109,579 -18.38 0.3138
2024-05-15 2024-03-31 13F DEXCOM COM 252131107 967,983 -29,725 -2.98 134,259 8.44 0.3578
2024-02-14 2023-12-31 13F DEXCOM COM 252131107 997,708 -321,358 -24.36 123,806 0.60 0.3297
2023-11-14 2023-09-30 13F DEXCOM COM 252131107 1,319,066 -107,924 -7.56 123,069 -32.89 0.3576
2023-08-14 2023-06-30 13F DEXCOM COM 252131107 1,426,990 -10,150 -0.71 183,382 9.83 0.5078
2023-05-15 2023-03-31 13F DEXCOM COM 252131107 1,437,140 81,553 6.02 166,967 8.77 0.5012
2023-02-14 2022-12-31 13F DEXCOM COM 252131107 1,355,587 -115,159 -7.83 153,507 29.59 0.5155
2022-11-14 2022-09-30 13F DEXCOM COM 252131107 1,470,746 672 0.05 118,454 8.11 0.3827
2022-08-15 2022-06-30 13F DEXCOM COM 252131107 1,470,074 1,100,105 297.35 109,565 -42.11 0.3519
2022-05-13 2022-03-31 13F DEXCOM COM 252131107 369,969 -10,919 -2.87 189,276 -7.45 0.4645
2022-02-14 2021-12-31 13F DEXCOM COM 252131107 380,888 -18,358 -4.60 204,518 -6.33 0.4338
2021-11-12 2021-09-30 13F DEXCOM COM 252131107 399,246 3,020 0.76 218,332 29.05 0.4945
2021-08-13 2021-06-30 13F DEXCOM COM 252131107 396,226 -19,311 -4.65 169,189 13.29 0.3874
2021-05-19 2021-03-31 13F DEXCOM COM 252131107 415,537 -992 -0.24 149,340 -3.03 0.3681
2021-02-12 2020-12-31 13F DEXCOM COM 252131107 416,529 -67 -0.02 153,999 -10.33 0.3810
2020-11-13 2020-09-30 13F DEXCOM COM 252131107 416,596 -55,080 -11.68 171,733 -10.19 0.5271
2020-08-14 2020-06-30 13F DEXCOM COM 252131107 471,676 -28,168 -5.64 191,217 42.07 0.6912
2020-05-15 2020-03-31 13F DEXCOM COM 252131107 499,844 -8,540 -1.68 134,593 21.03 0.6596
2020-02-18 2019-12-31 13F DEXCOM COM 252131107 508,384 471 0.09 111,204 46.71 0.4246
2019-11-14 2019-09-30 13F DEXCOM COM 252131107 507,913 7,669 1.53 75,801 1.13 0.3118
2019-08-15 2019-06-30 13F DEXCOM COM 252131107 500,244 86,347 20.86 74,957 52.06 0.3005
2019-05-15 2019-03-31 13F DEXCOM COM 252131107 413,897 111,916 37.06 49,295 36.26 0.2090
2019-02-14 2018-12-31 13F DEXCOM COM 252131107 301,981 320 0.11 36,177 -16.16 0.1831
2018-11-14 2018-09-30 13F DEXCOM COM 252131107 301,661 661 0.22 43,150 50.93 0.1788
2018-08-14 2018-06-30 13F DEXCOM COM 252131107 301,000 0 0.00 28,589 28.08 0.1250
2018-05-09 2018-03-31 13F DEXCOM COM 252131107 301,000 0 0.00 22,322 29.22 0.1027
2018-02-14 2017-12-31 13F DEXCOM COM 252131107 301,000 0 0.00 17,274 17.30 0.0796
2017-11-15 2017-09-30 13F DEXCOM COM 252131107 301,000 -379,810 -55.79 14,726 -70.43 0.0699
2017-08-14 2017-06-30 13F DEXCOM COM 252131107 680,810 -108,217 -13.72 49,801 -25.51 0.2544
2017-05-15 2017-03-31 13F DEXCOM COM 252131107 789,027 -50,000 -5.96 66,854 33.47 0.3540
2017-02-14 2016-12-31 13F DEXCOM COM 252131107 839,027 -12,450 -1.46 50,090 -32.89 0.2821
2016-11-15 2016-09-30 13F/A-1 DEXCOM COM 252131107 851,477 -50,200 -5.57 74,640 4.35 0.3957
2016-11-14 2016-09-30 13F DEXCOM COM 252131107 851,477 74,640
2016-08-15 2016-06-30 13F DEXCOM COM 252131107 901,677 -190,764 -17.46 71,530 -3.58 0.3803
2016-05-16 2016-03-31 13F DEXCOM COM 252131107 1,092,441 1,968 0.18 74,188 -16.93 0.3926
2016-02-16 2015-12-31 13F DEXCOM COM 252131107 1,090,473 -240,269 -18.06 89,310 -21.83 0.4136
2015-11-16 2015-09-30 13F DEXCOM COM 252131107 1,330,742 -6,865 -0.51 114,258 6.80 0.5159
2015-08-14 2015-06-30 13F DEXCOM COM 252131107 1,337,607 -800 -0.06 106,982 28.22 0.4206
2015-05-15 2015-03-31 13F DEXCOM COM 252131107 1,338,407 -2,324 -0.17 83,436 13.05 0.3228
2015-02-18 2014-12-31 13F/A-1 DEXCOM COM 252131107 1,340,731 -4,591 -0.34 73,807 37.19 0.2958
2015-02-17 2014-12-31 13F DEXCOM COM 252131107 1,340,731 73,807
2014-11-13 2014-09-30 13F DEXCOM COM 252131107 1,345,322 -3,250 -0.24 53,799 0.59 0.2229
2014-08-14 2014-06-30 13F DEXCOM COM 252131107 1,348,572 -5,540 -0.41 53,484 -4.50 0.2124
2014-05-15 2014-03-31 13F DEXCOM COM 252131107 1,354,112 -3,245 -0.24 56,006 16.52 0.2281
2014-02-18 2013-12-31 13F/A-1 DEXCOM COM 252131107 1,357,357 -11,797 48,064 0.1993
2014-05-15 2013-12-31 13F/A-2 DEXCOM COM 252131107 1,357,357 -11,797 -0.86 48,064 24.35 0.1993
2014-02-14 2013-12-31 13F DEXCOM COM 252131107 1,357,357 48,064
2013-11-14 2013-09-30 13F DEXCOM COM 252131107 1,369,154 -17,883 -1.29 38,651 24.12 0.1770
2013-08-14 2013-06-30 13F/A-1 DEXCOM COM 252131107 1,387,037 1,387,037 31,139 0.1621
2013-08-14 2013-06-30 13F DEXCOM COM 252131107 1,387,037 31,139 0.1621
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.