SION β€” Sionna Therapeutics Inc

Ownership history in Siren, L.L.C.  Β·  4 quarters on record

This page tracks every 13F SEC filing in which Siren, L.L.C. reported a position in Sionna Therapeutics Inc (SION). Data includes quarterly share count, position size as % of portfolio, estimated market value, and end-of-quarter stock price β€” sourced directly from SEC EDGAR 13F filings.

πŸ” Peak position
0.37% (2025 Q3)
πŸ“Š Avg. % of fund
0.31%
πŸ“… First filed
2025 Q1
πŸ“… Last filed
2025 Q4
⏱ Quarters held
4

Position Intelligence

Siren, L.L.C. Γ— SION AI Analytics

πŸ“ˆ Siren, L.L.C. outperformed the S&P 500 by +204.9% annually on this SION position. Average cost basis: $10.46. Maximum drawdown during holding period: –0.0%.

πŸ“ˆ Position Alpha vs SPY
+204.9%
annualised excess return

πŸ”₯ Exceptional β€” beat the S&P 500 by 204.9% per year on this position.
3 quarters analyzed

πŸ’° Entry Quality
$10.46
+293.3% vs current ($41.14)

Best entry: $10.46 (2025 Q1)  Β·  Worst: $10.46 (2025 Q1)

πŸ›‘οΈ Drawdown Resilience
–0.0%
max drawdown while held

πŸ’Ž No drawdown exceeding 20% during the holding period β€” exceptionally stable.

πŸ’ͺ Fund Conviction
50%
buy-side decisions

1 add Β· 1 trim. πŸ“ˆ More buys than sells across the holding period.

πŸ“‘ Position Trajectory
β†’ Stable
last 4–5 quarters trend

βš–οΈ Portfolio weight has remained relatively stable β€” conviction maintained.
Currently 0.37% of portfolio

⚠ Based on quarterly 13F SEC filings and end-of-quarter closing prices. Timing score = accuracy of add/trim decisions vs next-quarter price direction. Alpha = mean quarterly excess return Γ— 4 (annualised). Not investment advice.

% of Fund (quarterly)    SION price (monthly, adj. close)
πŸ“‹ Quarterly Holdings History 4 quarters  β–Ύ
Quarter Action Shares Change Chg % % of Fund Mkt Value Price (EOQ)
2025 Q4 REDUCED 300,000 -25,000 -7.7% 0.37% $12.3M $41.14
2025 Q3 UNCHANGED 325,000 β€” 0% 0.37% $9.6M $29.41
2025 Q2 UNCHANGED 325,000 β€” 0% 0.29% $5.6M $17.35
2025 Q1 INITIATED 325,000 β€” β€” 0.19% $3.4M $10.46

🏒 Other funds also holding SION

As of 2025 Q4 β€” sorted by position size

Atlas Venture Life Science Advisors, LLC 3Y 14.24% TPG GP A, LLC 3Y 10.33% RA CAPITAL MANAGEMENT, L.P. 3Y 7Y 4.17% SUPERSTRING CAPITAL MANAGEMENT LP 3.98% ORBIMED ADVISORS LLC 3Y 7Y 2.99% PERCEPTIVE ADVISORS LLC 3Y 7Y 0.86% Artia Global Partners LP 3Y 0.7% DEERFIELD MANAGEMENT COMPANY, L.P. 3Y 7Y 0.51% EVENTIDE ASSET MANAGEMENT, LLC 3Y 7Y 0.41% Soleus Capital Management, L.P. 3Y 0.41%
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