SPERO THERAPEUTICS INC

Ticker: SPRO CUSIP: 84833T103 Class: COM

RA CAPITAL MANAGEMENT, L.P.'s Holding History (CIK: 0001346824)

Note: Option positions (PUT/CALL) are excluded.

Q2 2018

Shares 741,647 Value ($000) $10,880 Avg Close $12.79 Range $10.12 - $19.00

Q1 2018

Shares 741,647 Value ($000) $10,568 Avg Close $12.13 Range $9.66 - $14.61

Q4 2017

Shares 1,225,647 Value ($000) $14,401 Avg Close $12.27 Range $9.85 - $15.40

Period	Shares	Value ($000)	Average Close	Price Range
Q2 2018	741,647	$10,880	$12.79	$10.12 - $19.00
Q1 2018	741,647	$10,568	$12.13	$9.66 - $14.61
Q4 2017	1,225,647	$14,401	$12.27	$9.85 - $15.40