Question 1

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

Accepted Answer

RA CAPITAL MANAGEMENT, L.P. previously held 0 shares of MBX (MBX Biosciences, Inc.) before exiting the position in 2025-Q3.

Question 2

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

Accepted Answer

RA CAPITAL MANAGEMENT, L.P.'s MBX position was last reported at $0 in 2025-Q3 before the exit.

Question 3

Is RA CAPITAL MANAGEMENT, L.P. buying or selling MBX?

Accepted Answer

In 2025-Q3, RA CAPITAL MANAGEMENT, L.P. exited their MBX position entirely (-100.0% change in shares).

Question 4

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

Accepted Answer

Based on available 13F filings, RA CAPITAL MANAGEMENT, L.P. first reported a position in MBX in 2024-Q3. They have held the position across 5 quarters.

Quarter	Action	Shares	Change	Value	Weight	Price	Conviction
2025-Q3 Latest	Exited	0	-100.0%	$0	0.0%	$17.94	0
2025-Q2	Decreased	377,841	-75.0%	$4.3M	0.1%	$10.75	0
2025-Q1	Unchanged	1.5M	0.0%	$11.2M	0.2%	$7.76	0
2024-Q4	Unchanged	1.5M	0.0%	$27.9M	0.4%	$17.91	0
2024-Q3	New	1.5M	—	$39.3M	0.5%	$23.95	48