Rock Springs Capital Management LP DYN DYNE THERAPEUTICS INC

Ownership history in Rock Springs Capital Management LP  ·  9 quarters on record

AI Ownership Summary

Rock Springs Capital Management LP reported DYNE THERAPEUTICS INC (DYN) in 9 quarterly 13F filings from 2024 Q1 through 2026 Q1. Peak portfolio weight reached 1.04% in 2026 Q1. The latest visible filing shows DYN at 1.04% 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 DYN ownership page tells you

This page is designed to answer the real investor question behind a 13F filing: how meaningful was Rock Springs Capital Management LP's position in DYNE THERAPEUTICS 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

DYN was reported at 1.04% of portfolio in the most recent visible filing.

High-water mark
Peak Conviction
1.04% in 2026 Q1

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

Time in book
Holding Window
2024 Q1 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.

How Rock Springs Capital Management LP held DYN — position size vs. price
% of Fund (quarterly)    DYN price (quarter-end, indexed to 100)    SPY (indexed to 100)    QQQ (indexed to 100)
📋 Quarterly Holdings History 9 quarters  
Quarter Action Sold % After 3M Timing Shares Change Chg % % of Fund Mkt Value Filed Price (Filed)
2026 Q1 ADDED 972,198 +59,243 +6.5% 1.04% $17.6M 2026-05-15 $17.29
2025 Q4 ADDED 912,955 +88,894 +10.8% 0.92% $17.9M 2026-02-17 $15.28
2025 Q3 ADDED 824,061 +243,063 +41.8% 0.61% $10.4M 2025-11-14 $18.79
2025 Q2 ADDED 580,998 +56,499 +10.8% 0.34% $5.5M 2025-08-14 $12.50
2025 Q1 ADDED 524,499 +49,971 +10.5% 0.31% $5.5M 2025-05-15 $11.74
2024 Q4 ADDED 474,528 +13,500 +2.9% 0.43% $11.2M 2025-02-14 $13.91
2024 Q3 UNCHANGED 461,028 0% 0.54% $16.6M 2024-11-14 $30.31
2024 Q2 ADDED 461,028 +9,204 +2.0% 0.49% $16.3M 2024-08-14 $43.88
2024 Q1 INITIATED 451,824 0.33% $12.8M 2024-05-15 $29.38

FAQ About Rock Springs Capital Management LP and DYN

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

How long has Rock Springs Capital Management LP reported owning DYN?

Rock Springs Capital Management LP reported DYN across 9 quarterly 13F filings, from 2024 Q1 through 2026 Q1.

What was the largest reported DYN position in Rock Springs Capital Management LP's portfolio?

The largest reported portfolio weight for DYN was 1.04% in 2026 Q1.

What is the latest reported DYN position on this page?

The most recent filing on this page is 2026 Q1, when Rock Springs Capital Management LP reported 972,198 shares, equal to 1.04% of portfolio, with an estimated market value of $17.6M.

What does the chart on this DYN ownership page compare?

The chart compares Rock Springs Capital Management LP's quarterly DYN 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.

How well did Rock Springs Capital Management LP time their DYN position?

Based on 13F filing dates vs. subsequent DYN price moves, Rock Springs Capital Management LP correctly timed 4 out of 7 reported position changes (57%). The annualised alpha on DYN relative to SPY over the holding period was +204.6%.

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