Rhythm Pharmaceuticals, Inc.
US ˙ NasdaqGM ˙ US76243J1051

SecurityRYTM / Rhythm Pharmaceuticals, Inc.
InstitutionBarclays Plc
Latest Disclosed Ownership131,436 shares
Latest Disclosed Value $ 14,068,909
Barclays Plc ownership in RYTM / Rhythm Pharmaceuticals, Inc.

On February 13, 2026 - Barclays Plc filed a 13F-HR form disclosing ownership of 131,436 shares of Rhythm Pharmaceuticals, Inc. (US:RYTM) valued at $14,068,909 USD as of December 31, 2025. The entity filed a previous 13F-HR/A on March 31, 2026 disclosing 142,385 shares of Rhythm Pharmaceuticals, Inc.. This represents a change in shares of -7.69% during the quarter. The current value of the position is $11,133,944 USD.

Barclays Plc has a history of taking positions in derivatives of the underlying security (RYTM) 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.

RYTM / Rhythm Pharmaceuticals, 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 RHYTHM PHARMACEUTICALS COM 76243J105 131,436 -10,949 -7.69 14,069 -2.16 0.0034
2026-03-31 2025-09-30 13F/A-3 RHYTHM PHARMACEUTICALS COM 76243J105 142,385 -208,813 -59.46 14,379 -35.21 0.0031
2026-03-19 2025-09-30 13F/A-2 RHYTHM PHARMACEUTICALS COM 76243J105 106,397 -244,801 5,574 0.0015
2025-11-12 2025-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 142,385 -208,813 14,379 0.0031
2026-02-27 2025-06-30 13F/A-2 RHYTHM PHARMACEUTICALS COM 76243J105 351,198 249,981 246.98 22,192 313.95 0.0051
2025-08-14 2025-06-30 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 351,198 249,981 22 0.0051
2025-08-13 2025-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 351,198 249,981 22 0.0017
2026-03-17 2025-03-31 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 101,217 -34,180 -25.24 5,361 -29.27 0.0015
2025-05-15 2025-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 101,217 -34,180 5 0.0015
2026-03-19 2024-12-31 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 135,397 29,000 27.26 7,580 35.97 0.0021
2025-02-13 2024-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 135,397 29,000 8 0.0021
2026-03-31 2024-09-30 13F/A-2 RHYTHM PHARMACEUTICALS COM 76243J105 106,397 52,766 98.39 5,574 153.13 0.0015
2024-11-19 2024-09-30 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 106,397 52,766 6 0.0015
2024-11-15 2024-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 106,397 52,766 6 0.0004
2026-03-23 2024-06-30 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 53,631 -73,905 -57.95 2,202 -60.15 0.0007
2024-08-14 2024-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 53,631 -73,905 2 0.0007
2026-03-24 2024-03-31 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 127,536 -123,879 -49.27 5,526 -52.18 0.0019
2024-05-15 2024-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 127,536 -123,879 6 0.0019
2026-03-25 2023-12-31 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 251,415 10,154 4.21 11,558 108.99 0.0042
2024-02-15 2023-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 251,415 10,154 12 0.0042
2026-03-26 2023-09-30 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 241,261 111,033 85.26 5,531 157.57 0.0034
2023-11-07 2023-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 241,261 111,033 6 0.0034
2026-03-30 2023-06-30 13F/A-2 RHYTHM PHARMACEUTICALS COM 76243J105 130,228 43,110 49.48 2,147 38.16 0.0014
2023-09-20 2023-06-30 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 130,228 43,110 2 0.0014
2023-08-03 2023-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 130,228 43,110 2 0.0014
2026-03-30 2023-03-31 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 87,118 -95,481 -52.29 1,554 -70.77 0.0007
2023-05-04 2023-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 87,118 -95,481 2 0.0007
2026-03-30 2022-12-31 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 182,599 18,246 11.10 5,317 32.03 0.0024
2023-02-13 2022-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 182,599 18,246 5 0.0024
2022-11-03 2022-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 164,353 155,063 1,669.14 4,027 10,225.64 0.0044
2022-08-12 2022-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 9,290 -11,909 -56.18 39 -84.08 0.0000
2022-05-16 2022-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 21,199 -32,270 -60.35 245 -54.03 0.0002
2022-02-23 2021-12-31 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 53,469 18,175 51.50 533 15.62 0.0002
2022-02-14 2021-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 53,469 18,175 533 0.0001
2021-11-09 2021-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 35,294 16,806 90.90 461 27.00 0.0002
2021-08-13 2021-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 18,488 -55,795 -75.11 363 -77.04 0.0002
2021-05-13 2021-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 74,283 39,527 113.73 1,581 53.05 0.0008
2021-02-11 2020-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 34,756 -62,369 -64.22 1,033 -50.93 0.0005
2020-11-12 2020-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 97,125 -4,726 -4.64 2,105 -7.27 0.0013
2020-08-12 2020-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 101,851 8,127 8.67 2,270 59.07 0.0018
2020-05-13 2020-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 93,724 -34,123 -26.69 1,427 -51.38 0.0011
2020-02-10 2019-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 127,847 113,881 815.42 2,935 871.85 0.0016
2019-11-15 2019-09-30 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 13,966 -4,521 -24.46 302 -25.62 0.0002
2019-11-14 2019-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 13,966 -4,521 302 69.8227
2019-08-14 2019-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 18,487 -1,036 -5.31 406 -24.25 0.0002
2019-05-15 2019-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 19,523 16,197 486.98 536 495.56 0.0004
2019-02-14 2018-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 3,326 -3,301 -49.81 90 -53.37 0.0001
2018-11-14 2018-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 6,627 5,302 400.15 193 370.73 0.0001
2018-08-14 2018-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,325 -2,843 -68.21 41 -51.19 0.0000
2018-05-15 2018-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 4,168 2,862 219.14 84 121.05 0.0001
2018-02-14 2017-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,306 1,306 38 0.0000
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
(%)
2024-11-19 2024-09-30 13F/A RHYTHM PHARMACEUTICALS OPT Call 0 0 n/a n/a n/a
2026-03-31 2024-09-30 13F/A RHYTHM PHARMACEUTICALS OPT Call 0 -100.00 0 -100.00 n/a n/a n/a
2024-11-15 2024-09-30 13F RHYTHM PHARMACEUTICALS OPT Call 0 0 n/a n/a n/a
2026-03-23 2024-06-30 13F/A RHYTHM PHARMACEUTICALS OPT Call 5,600 0.00 230 -5.37 n/a n/a n/a
2024-08-14 2024-06-30 13F RHYTHM PHARMACEUTICALS OPT Call 5,600 0 n/a n/a n/a
2026-03-24 2024-03-31 13F/A RHYTHM PHARMACEUTICALS OPT Call 5,600 0.00 243 -5.84 n/a n/a n/a
2024-05-15 2024-03-31 13F RHYTHM PHARMACEUTICALS OPT Call 5,600 0 n/a n/a n/a
2026-03-25 2023-12-31 13F/A RHYTHM PHARMACEUTICALS OPT Call 5,600 257 n/a n/a n/a
2024-02-15 2023-12-31 13F RHYTHM PHARMACEUTICALS OPT Call 5,600 0 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.