Question 1

How many shares of SION does RA CAPITAL MANAGEMENT, L.P. own?

Accepted Answer

As of 2026-Q1, RA CAPITAL MANAGEMENT, L.P. holds 9.9M shares of SION (SIONNA THERAPEUTICS INC).

Question 2

What is RA CAPITAL MANAGEMENT, L.P.'s SION position worth?

Accepted Answer

As of 2026-Q1, RA CAPITAL MANAGEMENT, L.P.'s SION position is worth $397.1M.

Question 3

When did RA CAPITAL MANAGEMENT, L.P. first buy SION?

Accepted Answer

Based on available 13F filings, RA CAPITAL MANAGEMENT, L.P. first reported a position in SION in 2025-Q1. They have held the position across 5 quarters.

Quarter	Action	Shares	Change	Value	Weight	Price	Conviction
2026-Q1 Latest	Unchanged	9.9M	0.0%	$397.1M	4.2%	$34.09	0
2025-Q4	Decreased	9.9M	-5.2%	$407.5M	4.2%	$41.39	0
2025-Q3	Unchanged	10.4M	0.0%	$307.2M	3.8%	$29.52	0
2025-Q2	Unchanged	10.4M	0.0%	$181.2M	3.1%	$15.84	0
2025-Q1	New	10.4M	—	$109.3M	1.8%	$11.56	69