Rhythm Pharmaceuticals, Inc.
MX ˙ BMV ˙ US76243J1051
SecurityMX:RYTM / Rhythm Pharmaceuticals, Inc.
InstitutionTower Research Capital LLC (TRC)
Latest Disclosed Ownership7,715 shares
Latest Disclosed Value $ 670,974
Tower Research Capital LLC (TRC) reports 160.47% increase in ownership of RYTM / Rhythm Pharmaceuticals, Inc.

On May 15, 2026 - Tower Research Capital LLC (TRC) filed a 13F-HR form disclosing ownership of 7,715 shares of Rhythm Pharmaceuticals, Inc. (MX:RYTM) valued at $670,974 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 2,962 shares of Rhythm Pharmaceuticals, Inc.. This represents a change in shares of 160.47% 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 RHYTHM PHARMACEUTICALS COM 76243J105 7,715 4,753 160.47 671 111.36 0.0115
2026-02-17 2025-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,962 1,209 68.97 317 79.10 0.0077
2025-11-14 2025-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,753 -4,358 -71.31 177 -54.15 0.0049
2025-08-15 2025-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 6,111 5,053 477.60 386 589.29 0.0104
2025-05-15 2025-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,058 -3,481 -76.69 56 -77.95 0.0017
2025-02-13 2024-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 4,539 4,161 1,100.79 254 1,236.84 0.0050
2024-11-14 2024-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 378 -9,547 -96.19 20 -95.33 0.0005
2024-08-13 2024-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 9,925 9,386 1,741.37 408 1,669.57 0.0069
2024-05-15 2024-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 539 -9,169 -94.45 23 -94.84 0.0006
2024-02-13 2023-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 9,708 8,764 928.39 446 2,023.81 0.0055
2023-11-14 2023-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 944 -2,806 -74.83 22 -65.57 0.0007
2023-08-14 2023-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 3,750 -13,463 -78.21 62 0.0021
2023-05-09 2023-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 17,213 3,463 25.19 0 0.0098
2023-02-10 2022-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 13,750 5,276 62.26 0 -100.00 0.0166
2022-11-10 2022-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 8,474 2,670 46.00 207 728.00 0.0034
2022-08-15 2022-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 5,804 -28,704 -83.18 25 -93.70 0.0006
2022-05-12 2022-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 34,508 31,990 1,270.45 397 1,488.00 0.0038
2022-02-14 2021-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,518 -679 -21.24 25 -39.02 0.0004
2021-11-15 2021-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 3,197 -538 -14.40 41 -43.84 0.0010
2021-08-16 2021-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 3,735 1,461 64.25 73 52.08 0.0019
2021-05-17 2021-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,274 1,490 190.05 48 108.70 0.0008
2021-02-16 2020-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 784 -1,233 -61.13 23 -47.73 0.0007
2020-11-16 2020-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,017 -767 -27.55 44 -29.03 0.0005
2020-08-13 2020-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,784 2,784 62 0.0025
2020-02-07 2019-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 0 -603 -100.00 0 -100.00
2019-11-05 2019-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 603 603 13 0.0009
2019-08-13 2019-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 0 -1,095 -100.00 0 -100.00
2019-05-14 2019-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,095 859 363.98 30 328.57 0.0018
2019-02-14 2018-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 236 187 381.63 7 600.00 0.0005
2018-11-13 2018-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 49 -375 -88.44 1 -92.31 0.0001
2018-08-14 2018-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 424 32 8.16 13 62.50 0.0007
2018-05-15 2018-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 392 392 8 0.0007
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.