iRhythm Holdings, Inc.
DE ˙ DB ˙ US4500561067
89,00 € ↑1,00 (1,14%)
2026-06-04
DEL PRIS
SecurityDE:I25 / iRhythm Holdings, Inc.
InstitutionHolocene Advisors, LP
Latest Disclosed Ownership1,248,658 shares
Latest Disclosed Value $ 147,366,617
Holocene Advisors, LP ownership in I25 / iRhythm Holdings, Inc.

On May 15, 2026 - Holocene Advisors, LP filed a 13F-HR form disclosing ownership of 1,248,658 shares of iRhythm Holdings, Inc. (DE:I25) valued at $122,368,484 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 683,568 shares of iRhythm Holdings, Inc.. This represents a change in shares of 82.67% during the quarter. The current value of the position is $111,130,562 USD.

Holocene Advisors, LP has a history of taking positions in derivatives of the underlying security (I25) in the form of stock options. The firm currently holds call 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.

DE:I25 / iRhythm Holdings, 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 IRHYTHM HOLDINGS COM 450056106 1,248,658 565,090 82.67 147,367 21.50 0.3554
2026-02-17 2025-12-31 13F IRHYTHM TECHNOLOGIES COM 450056106 683,568 210,288 44.43 121,292 49.01 0.2547
2025-11-14 2025-09-30 13F IRHYTHM TECHNOLOGIES COM 450056106 473,280 160,186 51.16 81,399 68.87 0.1855
2025-08-14 2025-06-30 13F IRHYTHM TECHNOLOGIES COM 450056106 313,094 298,347 2,023.10 48,204 3,023.98 0.1176
2025-05-15 2025-03-31 13F IRHYTHM TECHNOLOGIES COM 450056106 14,747 -71,106 -82.82 1,544 -80.07 0.0045
2025-02-14 2024-12-31 13F IRHYTHM TECHNOLOGIES COM 450056106 85,853 -95,132 -52.56 7,741 -42.39 0.0248
2024-11-14 2024-09-30 13F IRHYTHM TECHNOLOGIES COM 450056106 180,985 -861,685 -82.64 13,436 -88.03 0.0543
2024-08-14 2024-06-30 13F IRHYTHM TECHNOLOGIES COM 450056106 1,042,670 124,021 13.50 112,233 5.32 0.4685
2024-05-15 2024-03-31 13F IRHYTHM TECHNOLOGIES COM 450056106 918,649 -44,717 -4.64 106,563 3.34 0.3913
2024-02-14 2023-12-31 13F IRHYTHM TECHNOLOGIES COM 450056106 963,366 330,869 52.31 103,119 72.96 0.4019
2023-11-14 2023-09-30 13F IRHYTHM TECHNOLOGIES COM 450056106 632,497 205,141 48.00 59,619 33.73 0.2610
2023-08-14 2023-06-30 13F IRHYTHM TECHNOLOGIES COM 450056106 427,356 -55,071 -11.42 44,582 -25.49 0.1903
2023-05-15 2023-03-31 13F IRHYTHM TECHNOLOGIES COM 450056106 482,427 -278,015 -36.56 59,835 -16.00 0.2941
2023-02-14 2022-12-31 13F IRHYTHM TECHNOLOGIES COM 450056106 760,442 -216,325 -22.15 71,231 -41.79 0.4344
2022-11-14 2022-09-30 13F IRHYTHM TECHNOLOGIES COM 450056106 976,767 64,844 7.11 122,369 24.21 0.7818
2022-08-15 2022-06-30 13F IRHYTHM TECHNOLOGIES COM 450056106 911,923 160,415 21.35 98,515 -16.75 0.5950
2022-05-16 2022-03-31 13F IRHYTHM TECHNOLOGIES COM 450056106 751,508 120,110 19.02 118,340 59.25 0.6167
2022-02-14 2021-12-31 13F IRHYTHM TECHNOLOGIES COM 450056106 631,398 255,924 68.16 74,309 237.95 0.3868
2021-11-15 2021-09-30 13F IRHYTHM TECHNOLOGIES COM 450056106 375,474 300,808 402.87 21,988 343.84 0.1195
2021-08-16 2021-06-30 13F IRHYTHM TECHNOLOGIES COM 450056106 74,666 48,056 180.59 4,954 34.07 0.0280
2021-05-17 2021-03-31 13F IRHYTHM TECHNOLOGIES COM 450056106 26,610 -141,669 -84.19 3,695 -90.74 0.0232
2021-02-16 2020-12-31 13F IRHYTHM TECHNOLOGIES COM 450056106 168,279 -344,624 -67.19 39,917 -67.32 0.2519
2020-11-16 2020-09-30 13F IRHYTHM TECHNOLOGIES COM 450056106 512,903 508,187 10,775.81 122,127 22,226.69 0.9286
2020-08-14 2020-06-30 13F IRHYTHM TECHNOLOGIES COM 450056106 4,716 -415,034 -98.88 547 -98.40 0.0048
2020-05-15 2020-03-31 13F IRHYTHM TECHNOLOGIES COM 450056106 419,750 -332,912 -44.23 34,147 -33.37 0.3667
2020-02-14 2019-12-31 13F IRHYTHM TECHNOLOGIES COM 450056106 752,662 724,583 2,580.52 51,249 2,362.71 0.4593
2019-11-14 2019-09-30 13F IRHYTHM TECHNOLOGIES COM 450056106 28,079 28,079 2,081 0.0214
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
(%)
2020-02-14 2019-12-31 13F IRHYTHM TECHNOLOGIES COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-11-14 2019-09-30 13F IRHYTHM TECHNOLOGIES COM Call 100,000 7,411 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.