Rhythm Pharmaceuticals, Inc.
US ˙ NasdaqGM ˙ US76243J1051

SecurityRYTM / Rhythm Pharmaceuticals, Inc.
InstitutionState Street Corp
Latest Disclosed Ownership2,206,018 shares
Ownership 3.73%
State Street Corp ownership in RYTM / Rhythm Pharmaceuticals, Inc.

2024-01-23 - State Street Corp has filed an SC 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 2,206,018 shares of Rhythm Pharmaceuticals, Inc. (US:RYTM). This represents 3.73 percent ownership of the company. In their previous filing dated 2023-02-03 , State Street Corp had reported owning 3,180,698 shares, indicating a decrease of -30.64 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date		Effective
Date		Form Prev
Shares		 Latest
Shares		 ΔShares
(Percent)		 Ownership
(Percent)		 ΔOwnership
(Percent)
2024-01-23 2024-01-23 13G/A 3,180,698 2,206,018 -30.64 3.73 -33.87
2023-02-03 2023-02-03 13G 3,180,698 5.64

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

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 2,271,851 73,236 3.33 197,583 -16.04 0.0068
2026-02-13 2025-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,198,615 169,964 8.38 235,340 14.87 0.0079
2025-11-14 2025-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,028,651 121,050 6.35 204,873 69.96 0.0071
2025-08-14 2025-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,907,601 -63,132 -3.20 120,541 15.47 0.0045
2025-05-15 2025-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,970,733 129,863 7.05 104,390 1.30 0.0043
2025-02-14 2024-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,840,870 -152,296 -7.64 103,052 -1.31 0.0041
2024-11-14 2024-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,993,166 -10,716 -0.53 104,422 26.91 0.0042
2024-08-14 2024-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,003,882 -1,009,956 -33.51 82,279 -36.99 0.0036
2024-05-15 2024-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 3,013,838 807,820 36.62 130,590 28.77 0.0058
2024-02-14 2023-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,206,018 -159,838 -6.76 101,411 86.98 0.0049
2023-11-14 2023-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,365,856 -901,569 -27.59 54,237 0.66 0.0030
2023-08-14 2023-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 3,267,425 655,237 25.08 53,880 15.62 0.0028
2023-05-15 2023-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,612,188 -568,510 -17.87 46,601 -49.69 0.0026
2023-05-15 2022-12-31 13F/A-99 RHYTHM PHARMACEUTICALS COM 76243J105 3,180,698 52,793 1.69 92,622 20.86 0.0054
2023-05-15 2022-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 3,180,698 52,793 92,622 0.0054
2022-11-15 2022-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 3,127,905 2,876,846 1,145.88 76,634 7,254.51 0.0048
2022-08-15 2022-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 251,059 -560,124 -69.05 1,042 -88.85 0.0001
2022-05-16 2022-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 811,183 -1,119,907 -57.99 9,345 -51.51 0.0005
2022-02-14 2021-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,931,090 -293,627 -13.20 19,272 -33.67 0.0009
2021-11-15 2021-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,224,717 45,630 2.09 29,055 -31.90 0.0015
2021-08-16 2021-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,179,087 -262,293 -10.74 42,667 -17.83 0.0022
2021-07-09 2021-03-31 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 2,441,380 1,162,261 90.86 51,928 36.55 0.0030
2021-05-17 2021-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,441,380 1,162,261 51,928 0.0030
2021-02-16 2020-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,279,119 395,139 44.70 38,028 98.52 0.0023
2020-11-10 2020-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 883,980 -252,512 -22.22 19,156 -24.42 0.0013
2020-08-14 2020-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,136,492 158,791 16.24 25,344 70.31 0.0018
2020-06-19 2020-03-31 13F/A-1 RHYTHM PHARMACEUTICALS COM 76243J105 977,701 45,181 4.85 14,881 -30.50 0.0013
2020-05-11 2020-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 977,701 45,181 14,881 1,306.8514
2020-02-06 2019-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 932,520 214,980 29.96 21,411 38.21 0.0015
2019-11-14 2019-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 717,540 113,164 18.72 15,492 16.52 0.0012
2019-08-14 2019-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 604,376 131,990 27.94 13,296 2.69 0.0010
2019-05-15 2019-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 472,386 -12,637 -2.61 12,948 -0.68 0.0010
2019-02-12 2018-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 485,023 -199,049 -29.10 13,037 -34.66 0.0012
2018-11-09 2018-09-30 13F RHYTHM PHARMACEUTICLS Common equity shares 76243J105 684,072 481,187 237.17 19,954 214.53 0.0015
2018-08-14 2018-06-30 13F RHYTHM PHARMACEUTICLS Common equity shares 76243J105 202,885 87,931 76.49 6,344 177.15 0.0005
2018-05-15 2018-03-31 13F RHYTHM PHARMACEUTICLS Common equity shares 76243J105 114,954 17,660 18.15 2,289 -19.06 0.0002
2018-02-14 2017-12-31 13F RHYTHM PHARMACEUTICLS Common equity shares 76243J105 97,294 97,294 2,828 0.0002
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.