HUDSON TECHNOLOGIES INC

Ticker: HDSN CUSIP: 444144109 Class: Common Stock

WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC's Holding History (CIK: 0001644956)

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

Q1 2017

Shares 825,505 Value ($000) $5,448 Avg Close $7.28 Range $6.02 - $8.28

Q4 2016

Shares 878,533 Value ($000) $7,037 Avg Close $7.06 Range $5.55 - $8.50

Q3 2016

Shares 1,663,985 Value ($000) $11,066 Avg Close $5.28 Range $3.26 - $6.72

Q2 2016

Shares 3,369,429 Value ($000) $12,130 Avg Close $3.41 Range $3.09 - $3.95

Q1 2016

Shares 3,243,055 Value ($000) $10,637 Avg Close $3.15 Range $2.64 - $3.69

Q4 2015

Shares 3,041,164 Value ($000) $9,032 Avg Close $3.09 Range $2.69 - $3.56

Q3 2015

Shares 3,000,198 Value ($000) $8,911 Avg Close $3.15 Range $2.45 - $3.58

Period	Shares	Value ($000)	Average Close	Price Range
Q1 2017	825,505	$5,448	$7.28	$6.02 - $8.28
Q4 2016	878,533	$7,037	$7.06	$5.55 - $8.50
Q3 2016	1,663,985	$11,066	$5.28	$3.26 - $6.72
Q2 2016	3,369,429	$12,130	$3.41	$3.09 - $3.95
Q1 2016	3,243,055	$10,637	$3.15	$2.64 - $3.69
Q4 2015	3,041,164	$9,032	$3.09	$2.69 - $3.56
Q3 2015	3,000,198	$8,911	$3.15	$2.45 - $3.58