DexCom, Inc.
MX ˙ BMV ˙ US2521311074
SecurityMX:DXCM / DexCom, Inc.
InstitutionPrelude Capital Management, Llc
Latest Disclosed Ownership5,543 shares
Latest Disclosed Value $ 348,100
Prelude Capital Management, Llc ownership in DXCM / DexCom, Inc.

On May 15, 2026 - Prelude Capital Management, Llc filed a 13F-HR form disclosing ownership of 5,543 shares of DexCom, Inc. (MX:DXCM) valued at $348,100 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 16,361 shares of DexCom, Inc.. This represents a change in shares of -66.12% during the quarter.

Prelude Capital Management, Llc has a history of taking positions in derivatives of the underlying security (DXCM) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD and put options representing 0 of underlying shares valued at $0 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.

MX: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)
2026-05-15 2026-03-31 13F DEXCOM COM 252131107 5,543 -10,818 -66.12 348 -67.93 0.0266
2026-02-17 2025-12-31 13F DEXCOM COM 252131107 16,361 13,157 410.64 1,086 404.65 0.0799
2025-11-14 2025-09-30 13F DEXCOM COM 252131107 3,204 3,204 216 0.0168
2025-08-14 2025-06-30 13F DEXCOM COM 252131107 0 -3,823 -100.00 0 -100.00
2025-05-15 2025-03-31 13F DEXCOM COM 252131107 3,823 3,823 261 0.0198
2024-11-14 2024-09-30 13F/A-1 DEXCOM COM 252131107 0 -15,189 -100.00 0 -100.00
2024-11-14 2024-09-30 13F DEXCOM COM 252131107 0 0
2024-08-14 2024-06-30 13F DEXCOM COM 252131107 15,189 -1,001 -6.18 1,722 -23.30 0.1195
2024-05-15 2024-03-31 13F DEXCOM COM 252131107 16,190 16,190 2,246 0.1179
2024-02-14 2023-12-31 13F DEXCOM COM 252131107 0 -17,664 -100.00 0 -100.00
2023-11-14 2023-09-30 13F DEXCOM COM 252131107 17,664 17,664 1,648 0.1074
2023-08-14 2023-06-30 13F DEXCOM COM 252131107 0 -3,085 -100.00 0 -100.00
2023-06-01 2023-03-31 13F/A-1 DEXCOM COM 252131107 3,085 -9,787 -76.03 358 -75.43 0.0215
2023-05-15 2023-03-31 13F DEXCOM COM 252131107 3,085 -9,787 358 0.0117
2023-02-14 2022-12-31 13F DEXCOM COM 252131107 12,872 -2,172 -14.44 1,458 20.21 0.0757
2022-11-14 2022-09-30 13F DEXCOM COM 252131107 15,044 -375 -2.43 1,212 5.48 0.0435
2022-08-24 2022-06-30 13F/A-1 DEXCOM COM 252131107 15,419 10,126 191.31 1,149 -57.57 0.0327
2022-08-15 2022-06-30 13F DEXCOM COM 252131107 15,419 10,126 1,149 0.0327
2022-05-16 2022-03-31 13F DEXCOM COM 252131107 5,293 3,753 243.70 2,708 227.45 0.0778
2022-02-14 2021-12-31 13F DEXCOM COM 252131107 1,540 3 0.20 827 -1.66 0.0212
2021-11-15 2021-09-30 13F DEXCOM COM 252131107 1,537 1,537 841 0.0215
2021-05-17 2021-03-31 13F DEXCOM COM 252131107 0 -943 -100.00 0 -100.00
2021-02-16 2020-12-31 13F DEXCOM COM 252131107 943 -849 -47.38 349 -52.77 0.0089
2020-11-16 2020-09-30 13F DEXCOM COM 252131107 1,792 481 36.69 739 39.17 0.0357
2020-08-14 2020-06-30 13F DEXCOM COM 252131107 1,311 1,311 -26.84 531 -28.15 0.0292
2019-08-14 2019-06-30 13F DEXCOM COM 252131107 0 -7,960 -100.00 0 -100.00
2019-05-15 2019-03-31 13F DEXCOM COM 252131107 7,960 -2,883 -26.59 948 -27.02 0.0534
2019-02-14 2018-12-31 13F DEXCOM COM 252131107 10,843 2,737 33.77 1,299 12.08 0.0870
2018-11-14 2018-09-30 13F DEXCOM COM 252131107 8,106 -2,770 -25.47 1,159 12.20 0.0673
2018-08-14 2018-06-30 13F DEXCOM COM 252131107 10,876 -1,069 -8.95 1,033 16.59 0.0654
2018-05-15 2018-03-31 13F DEXCOM COM 252131107 11,945 11,945 9.83 886 -14.23 0.0643
2016-08-15 2016-06-30 13F DEXCOM COM 252131107 0 -1,421 -100.00 0 -100.00
2016-05-16 2016-03-31 13F DEXCOM COM 252131107 1,421 1,414 20,200.00 97 9,600.00 0.0135
2016-02-16 2015-12-31 13F DEXCOM COM 252131107 7 7 -99.51 1 -98.97 0.0002
2015-05-15 2015-03-31 13F DEXCOM COM 252131107 0 -700 -100.00 0 -100.00
2015-02-13 2014-12-31 13F DEXCOM COM 252131107 700 700 39 0.0057
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
(%)
2018-05-15 2018-03-31 13F DEXCOM COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-02-14 2017-12-31 13F DEXCOM COM Call 18,300 19.61 1,050 40.19 n/a n/a n/a
2017-11-14 2017-09-30 13F DEXCOM COM Call 15,300 -10.53 749 -40.13 n/a n/a n/a
2017-08-14 2017-06-30 13F DEXCOM COM Call 17,100 -16.99 1,251 -28.31 n/a n/a n/a
2017-05-15 2017-03-31 13F DEXCOM COM Call 20,600 49.28 1,745 111.77 n/a n/a n/a
2017-02-14 2016-12-31 13F DEXCOM COM Call 13,800 824 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
(%)
2020-02-14 2019-12-31 13F DEXCOM COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-11-14 2019-09-30 13F DEXCOM COM Put 100 0.00 15 0.00 n/a n/a n/a
2019-08-14 2019-06-30 13F DEXCOM COM Put 100 15 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.