S&CO INC RARE — ULTRAGENYX PHARMACEUTICAL, INC

Ownership history in S&CO INC  ·  8 quarters on record

AI Ownership Summary

S&CO INC reported ULTRAGENYX PHARMACEUTICAL, INC (RARE) in 8 quarterly 13F filings from 2024 Q2 through 2026 Q1. Peak portfolio weight reached 0.07% in 2024 Q3. The latest visible filing shows RARE at 0.03% of the fund.

This page tracks quarterly shares, estimated market value, portfolio weight, filing dates, and disclosure-aligned stock prices directly from SEC EDGAR 13F filings.

What this RARE ownership page tells you

This page is designed to answer the real investor question behind a 13F filing: how meaningful was S&CO INC's position in ULTRAGENYX PHARMACEUTICAL, INC, and how did that conviction change over time? You can read the holding window, peak weight, latest reported size, disclosure timing, and quarter-by-quarter changes without piecing the story together from raw SEC rows.

Freshest filing
Latest Reported Filing
2026 Q1

RARE was reported at 0.03% of portfolio in the most recent visible filing.

High-water mark
Peak Conviction
0.07% in 2024 Q3

Peak weight helps separate a token disclosure from a real conviction holding the fund genuinely cared about.

Time in book
Holding Window
2024 Q2 to 2026 Q1

Longer holding windows often tell a very different story from short-lived tactical trades or one-quarter experiments.

Decision context
Why It Matters
Position size beats headlines

Knowing that a fund owned a stock is useful. Knowing whether it was a 0.20% placeholder or a true high-conviction position is where the signal actually starts.

RARE stock page S&CO INC fund profile S&CO INC full holdings
How S&CO INC held RARE — position size vs. price
% of Fund (quarterly)    RARE price (quarter-end, indexed to 100)    SPY (indexed to 100)    QQQ (indexed to 100)
📋 Quarterly Holdings History 8 quarters  ▾
Quarter Action Sold % After 3M Timing Shares Change Chg % % of Fund Mkt Value Filed Price (Filed)
2026 Q1 UNCHANGED — — — 25,255 — 0% 0.03% $529 2026-05-07 $26.03
2025 Q4 UNCHANGED — — — 25,255 — 0% 0.04% $580K 2026-02-05 $23.79
2025 Q3 UNCHANGED — — — 25,255 — 0% 0.05% $759K 2025-11-06 $30.95
2025 Q2 ADDED — — — 25,255 +5,000 +24.7% 0.06% $918K 2025-08-07 $27.83
2025 Q1 UNCHANGED — — — 20,255 — 0% 0.05% $733K 2025-05-08 $35.98
2024 Q4 UNCHANGED — — — 20,255 — 0% 0.06% $852K 2025-02-07 $45.35
2024 Q3 UNCHANGED — — — 20,255 — 0% 0.07% $1.1M 2024-11-07 $50.43
2024 Q2 INITIATED — — — 20,255 — — 0.06% $832K 2024-08-08 $50.29

🏢 Other funds also holding RARE

As of 2026 Q1 — sorted by position size

Privium Fund Management B.V. 3Y 1.59% PSP Research LLC 0.33% HARBOR CAPITAL ADVISORS, INC. 3Y 0.14% Candriam S.C.A. 3Y 7Y 0.12% Y-Intercept (Hong Kong) Ltd 3Y 0.09% FIDEURAM - INTESA SANPAOLO PRIVATE BANKING S.P.A. 0.07% Assenagon Asset Management S.A. 3Y 7Y 0.07% PROFUND ADVISORS LLC 3Y 7Y 0.06% Crestwood Advisors Group, LLC 3Y 7Y 0.04% PINNACLE ASSOCIATES LTD 3Y 7Y 0.03%

FAQ About S&CO INC and RARE

These are the practical questions this page is built to answer before you even open the full history table.

How long has S&CO INC reported owning RARE?

S&CO INC reported RARE across 8 quarterly 13F filings, from 2024 Q2 through 2026 Q1.

What was the largest reported RARE position in S&CO INC's portfolio?

The largest reported portfolio weight for RARE was 0.07% in 2024 Q3.

What is the latest reported RARE position on this page?

The most recent filing on this page is 2026 Q1, when S&CO INC reported 25,255 shares, equal to 0.03% of portfolio, with an estimated market value of $529.

What does the chart on this RARE ownership page compare?

The chart compares S&CO INC's quarterly RARE portfolio weight with the stock's indexed share price, so you can see whether the fund was building, trimming, or holding the position as price moved.

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