Rhythm Pharmaceuticals, Inc.
US ˙ NasdaqGM ˙ US76243J1051

SecurityRYTM / Rhythm Pharmaceuticals, Inc.
InstitutionQUANTITATIVE MASTER SERIES LLC - Master Small Cap Index Series
Latest Disclosed Ownership93,840 shares
Latest Disclosed Value $ 5,929,749
QUANTITATIVE MASTER SERIES LLC - Master Small Cap Index Series reports 0.58% increase in ownership of RYTM / Rhythm Pharmaceuticals, Inc.

On August 26, 2025 - QUANTITATIVE MASTER SERIES LLC - Master Small Cap Index Series filed a NPORT-P form disclosing ownership of 93,840 shares of Rhythm Pharmaceuticals, Inc. (US:RYTM) valued at $5,929,750 USD as of June 30, 2025. The entity filed a previous NPORT-P on May 28, 2025 disclosing 93,303 shares of Rhythm Pharmaceuticals, Inc.. This represents a change in shares of 0.58% during the quarter. The current value of the position is $8,107,776 USD.

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 .

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)
2025-08-26 2025-06-30 NP Rhythm Pharmaceuticals EC US76243J1051 93,840 537 0.58 5,930 19.97 0.1332
2025-05-28 2025-03-31 NP Rhythm Pharmaceuticals EC US76243J1051 93,303 990 1.07 4,942 -4.35 0.1186
2025-02-25 2024-12-31 NP Rhythm Pharmaceuticals EC US76243J1051 92,313 -16,028 -14.79 5,168 -8.95 0.1128
2024-11-26 2024-09-30 NP Rhythm Pharmaceuticals EC US76243J1051 108,341 7,576 7.52 5,676 37.18 0.1073
2024-08-26 2024-06-30 NP Rhythm Pharmaceuticals EC US76243J1051 100,765 10,063 11.09 4,137 5.27 0.0843
2024-05-28 2024-03-31 NP Rhythm Pharmaceuticals EC US76243J1051 90,702 -2,184 -2.35 3,930 -7.94 0.0820
2024-02-26 2023-12-31 NP Rhythm Pharmaceuticals EC US76243J1051 92,886 5,756 6.61 4,270 113.77 0.0911
2023-11-28 2023-09-30 NP Rhythm Pharmaceuticals EC US76243J1051 87,130 -1,520 -1.71 1,997 36.69 0.0521
2023-08-25 2023-06-30 NP Rhythm Pharmaceuticals EC US76243J1051 88,650 20,842 30.74 1,462 87.07 0.0347
2022-05-26 2022-03-31 NP Rhythm Pharmaceuticals EC US76243J1051 67,808 0 0.00 781 15.53 0.0182
2022-02-25 2021-12-31 NP Rhythm Pharmaceuticals EC US76243J1051 67,808 0 0.00 677 -23.62 0.0147
2021-11-24 2021-09-30 NP Rhythm Pharmaceuticals EC US76243J1051 67,808 0 0.00 886 -33.31 0.0195
2021-08-26 2021-06-30 NP Rhythm Pharmaceuticals EC US76243J1051 67,808 10,242 17.79 1,328 8.42 0.0285
2021-05-27 2021-03-31 NP Rhythm Pharmaceuticals EC US76243J1051 57,566 3,895 7.26 1,224 -23.26 0.0278
2021-02-25 2020-12-31 NP Rhythm Pharmaceuticals EC US76243J1051 53,671 0 0.00 1,596 37.15 0.0409
2020-11-25 2020-09-30 NP Rhythm Pharmaceuticals EC US76243J1051 53,671 -3,130 -5.51 1,163 -8.14 0.0373
2020-08-27 2020-06-30 NP Rhythm Pharmaceuticals EC US76243J1051 56,801 7,836 16.00 1,267 69.93 0.0414
2020-06-01 2020-03-31 NP Rhythm Pharmaceuticals EC US76243J1051 48,965 -4,110 -7.74 745 -38.83 0.0305
2020-02-27 2019-12-31 NP Rhythm Pharmaceuticals EC 76243J105 53,075 18,205 52.21 1,219 61.97 0.0366
2019-11-27 2019-09-30 NP Rhythm Pharmaceuticals EC US76243J1051 34,870 34,870 753 0.0249
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.