Rhythm Pharmaceuticals, Inc.
MX ˙ BMV ˙ US76243J1051
SecurityMX:RYTM / Rhythm Pharmaceuticals, Inc.
InstitutionWellington Management Group Llp
Latest Disclosed Ownership2,101,227 shares
Ownership 4.75%
Wellington Management Group Llp ownership in RYTM / Rhythm Pharmaceuticals, Inc.

2021-02-04 - Wellington Management Group Llp has filed an SC 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 2,101,227 shares of Rhythm Pharmaceuticals, Inc. (MX:RYTM). This represents 4.75 percent ownership of the company. In their previous filing dated 2020-01-28 , Wellington Management Group Llp had reported owning 3,320,751 shares, indicating a decrease of -36.72 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)
2021-02-04 2021-02-04 13G/A 3,320,751 2,101,227 -36.72 4.75 -37.17
2020-01-28 2020-01-28 13G 3,320,751 7.56

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 273,757 23,601 9.43 23,809 -11.08 0.0006
2026-02-17 2025-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 250,156 225,679 922.00 26,777 983.61 0.0047
2025-11-14 2025-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 24,477 2,052 9.15 2,472 74.38 0.0004
2025-08-14 2025-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 22,425 -1,133 -4.81 1,417 13.63 0.0003
2025-05-13 2025-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 23,558 -1,997 -7.81 1,248 -12.80 0.0002
2025-02-12 2024-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 25,555 -2,161 -7.80 1,431 -1.52 0.0003
2024-11-14 2024-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 27,716 -174,610 -86.30 1,452 -82.52 0.0003
2024-08-14 2024-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 202,326 8,803 4.55 8,308 -0.93 0.0015
2024-05-15 2024-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 193,523 53,721 38.43 8,385 30.49 0.0015
2024-02-12 2023-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 139,802 2,359 1.72 6,427 104.00 0.0012
2023-11-14 2023-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 137,443 -2,778 -1.98 3,151 36.25 0.0006
2023-08-14 2023-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 140,221 28,588 25.61 2,312 16.12 0.0004
2023-05-12 2023-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 111,633 4,717 4.41 1,992 -36.04 0.0004
2023-02-13 2022-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 106,916 -46,297 -30.22 3,113 -17.08 0.0006
2022-11-14 2022-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 153,213 67,648 79.06 3,754 957.46 0.0008
2022-08-15 2022-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 85,565 -246 -0.29 355 -64.11 0.0001
2022-05-16 2022-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 85,811 -660,072 -88.50 989 -86.71 0.0002
2022-02-11 2021-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 745,883 -100,069 -11.83 7,444 -32.62 0.0012
2021-11-15 2021-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 845,952 -450,129 -34.73 11,048 -56.46 0.0019
2021-08-16 2021-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,296,081 280,779 27.65 25,377 17.51 0.0042
2021-05-17 2021-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,015,302 -1,085,925 -51.68 21,595 -65.43 0.0038
2021-02-12 2020-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,101,227 -273,121 -11.50 62,469 21.41 0.0115
2020-11-16 2020-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,374,348 -222,575 -8.57 51,452 -11.16 0.0106
2020-08-14 2020-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,596,923 -71,305 -2.67 57,913 42.60 0.0129
2020-05-14 2020-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 2,668,228 -652,523 -19.65 40,611 -46.74 0.0107
2020-02-11 2019-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 3,320,751 2,206,404 198.00 76,244 216.90 0.0160
2019-11-13 2019-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 1,114,347 571,717 105.36 24,059 101.53 0.0054
2019-08-14 2019-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 542,630 -37,149 -6.41 11,938 -24.88 0.0026
2019-05-15 2019-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 579,779 -22,735 -3.77 15,892 -1.88 0.0036
2019-02-14 2018-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 602,514 234,224 63.60 16,196 50.76 0.0041
2018-11-14 2018-09-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 368,290 8,215 2.28 10,743 -4.57 0.0023
2018-08-14 2018-06-30 13F RHYTHM PHARMACEUTICALS COM 76243J105 360,075 -185,181 -33.96 11,257 3.74 0.0025
2018-05-15 2018-03-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 545,256 0 0.00 10,851 -31.52 0.0025
2018-02-13 2017-12-31 13F RHYTHM PHARMACEUTICALS COM 76243J105 545,256 545,256 15,845 0.0035
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.