Rhythm Pharmaceuticals, Inc.
MX ˙ BMV ˙ US76243J1051
SecurityMX:RYTM / Rhythm Pharmaceuticals, Inc.
InstitutionJpmorgan Chase & Co
Latest Disclosed Ownership1,553,644 shares
Latest Disclosed Value $ 120,019,069
Jpmorgan Chase & Co ownership in RYTM / Rhythm Pharmaceuticals, Inc.

On May 13, 2026 - Jpmorgan Chase & Co filed a 13F-HR/A form disclosing ownership of 1,553,644 shares of Rhythm Pharmaceuticals, Inc. (MX:RYTM) valued at $120,019,069 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 1,423,989 shares of Rhythm Pharmaceuticals, Inc.. This represents a change in shares of 9.11% during the quarter.

Jpmorgan Chase & Co has a history of taking positions in derivatives of the underlying security (RYTM) 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.

Upgrade to unlock premium data and export to Excel .

Institutional Put/Call Ratios
(Premium Subscription Required)

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: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)
2026-05-13 2026-03-31 13F/A-1 RHYTHM PHARMACEUTICALS COMMON 76243J105 1,553,644 129,655 9.11 120,019 -21.26 0.0008
2026-02-11 2025-12-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 1,423,989 235,920 19.86 152,424 27.04 0.0096
2025-11-26 2025-09-30 13F/A-1 RHYTHM PHARMACEUTICALS COMMON 76243J105 1,188,069 404,510 51.62 119,983 142.33 0.0072
2025-11-07 2025-09-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 1,188,069 404,510 119,983 0.0072
2025-08-12 2025-06-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 783,559 639,919 445.50 49,513 550.80 0.0032
2025-05-12 2025-03-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 143,640 -120,945 -45.71 7,609 -48.63 0.0006
2025-02-12 2024-12-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 264,585 182,993 224.28 14,811 246.54 0.0011
2024-12-26 2024-09-30 13F/A-1 RHYTHM PHARMACEUTICALS COMMON 76243J105 81,592 -58,554 -41.78 4,275 -25.72 0.0003
2024-11-08 2024-09-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 81,592 -58,554 4,275 0.0003
2024-12-26 2024-06-30 13F/A-1 RHYTHM PHARMACEUTICALS COMMON 76243J105 140,146 85,642 157.13 5,754 143.71 0.0005
2024-08-12 2024-06-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 140,146 85,642 5,754 0.0005
2024-12-26 2024-03-31 13F/A-1 RHYTHM PHARMACEUTICALS COMMON 76243J105 54,504 -23,095 -29.76 2,362 -33.81 0.0002
2024-05-10 2024-03-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 54,504 -23,095 2,362 0.0002
2024-12-26 2023-12-31 13F/A-1 RHYTHM PHARMACEUTICALS COMMON 76243J105 77,599 5,188 7.16 3,567 114.88 0.0003
2024-02-12 2023-12-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 77,599 5,188 3,567 0.0003
2023-11-14 2023-09-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 72,411 2,823 4.06 1,660 44.73 0.0002
2023-08-11 2023-06-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 69,588 47,303 212.26 1,148 188.19 0.0001
2023-05-18 2023-03-31 13F/A-1 RHYTHM PHARMACEUTICALS COMMON 76243J105 22,285 2,644 13.46 398 0.0000
2023-05-11 2023-03-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 484 -19,157 398 0.0000
2023-02-13 2022-12-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 19,641 17,430 788.33 1 -100.00 0.0001
2022-11-14 2022-09-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 2,211 1,770 401.36 54 2,600.00 0.0000
2022-08-11 2022-06-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 441 -26,540 -98.37 2 -99.36 0.0000
2022-05-11 2022-03-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 26,981 4,701 21.10 312 39.91 0.0000
2022-02-11 2021-12-31 13F/A-1 RHYTHM PHARMACEUTICALS COMMON 76243J105 22,280 -221 -0.98 223 -23.89 0.0000
2022-02-10 2021-12-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 22,280 -221 223 0.0000
2021-11-12 2021-09-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 22,501 332 1.50 293 -32.49 0.0000
2021-08-12 2021-06-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 22,169 -57,656 -72.23 434 -74.46 0.0001
2021-05-12 2021-03-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 79,825 -8,435 -9.56 1,699 -35.25 0.0002
2021-02-19 2020-12-31 13F/A-1 RHYTHM PHARMACEUTICALS COMMON 76243J105 88,260 -2,594 -2.86 2,624 29.71 0.0004
2021-02-11 2020-12-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 88,260 -2,594 2,624 64.8934
2020-11-12 2020-09-30 13F/A-1 RHYTHM PHARMACEUTICALS COMMON 76243J105 90,854 -5,017 -5.23 2,023 -5.33 0.0003
2020-11-12 2020-09-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 90,854 2,023
2020-08-11 2020-06-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 95,871 -8,145 -7.83 2,137 35.00 0.0004
2020-05-12 2020-03-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 104,016 -16,867 -13.95 1,583 -42.98 0.0004
2020-02-11 2019-12-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 120,883 -5,661 -4.47 2,776 1.61 0.0005
2019-11-12 2019-09-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 126,544 -291 -0.23 2,732 -0.69 0.0005
2019-08-07 2019-06-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 126,835 3,057 2.47 2,751 -18.92 0.0005
2019-05-07 2019-03-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 123,778 -321 -0.26 3,393 1.71 0.0007
2019-02-11 2018-12-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 124,099 -5,255 -4.06 3,336 -11.61 0.0008
2018-11-13 2018-09-30 13F/A-1 RHYTHM PHARMACEUTICALS COMMON 76243J105 129,354 -29,720 -18.68 3,774 -24.11 0.0007
2018-11-07 2018-09-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 129,354 -29,720 3,774
2018-08-14 2018-06-30 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 159,074 1,621 1.03 4,973 58.68 0.0010
2018-05-10 2018-03-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 157,453 39,476 33.46 3,134 -8.58 0.0007
2018-02-13 2017-12-31 13F RHYTHM PHARMACEUTICALS COMMON 76243J105 117,977 117,977 3,428 0.0007
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
(%)
2024-08-12 2024-06-30 13F RHYTHM PHARMACEUTICALS OPTION Put 0 -100.00 0 -100.00 n/a n/a n/a
2024-12-26 2024-03-31 13F/A RHYTHM PHARMACEUTICALS OPTION Put 100,000 4,333 n/a n/a n/a
2024-05-10 2024-03-31 13F RHYTHM PHARMACEUTICALS OPTION Put 100,000 4,333 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.