AMPHASTAR PHARMACEUTICALS IN

Ticker: AMPH CUSIP: 03209R103 Class: Common Stock

ESSEX INVESTMENT MANAGEMENT CO LLC's Holding History (CIK: 0000201772)

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

Q4 2016

Shares 63,661 Value ($000) $1,173 Avg Close $19.45 Range $16.87 - $21.75

Q3 2016

Shares 121,666 Value ($000) $2,308 Avg Close $18.15 Range $15.62 - $21.53

Q2 2016

Shares 105,239 Value ($000) $1,696 Avg Close $14.11 Range $11.41 - $16.78

Q1 2016

Shares 31,317 Value ($000) $376 Avg Close $11.79 Range $10.50 - $14.18

Q4 2015

Shares 31,317 Value ($000) $446 Avg Close $13.21 Range $10.57 - $15.84

Q3 2015

Shares 39,017 Value ($000) $456 Avg Close $15.00 Range $10.61 - $18.30

Period	Shares	Value ($000)	Average Close	Price Range
Q4 2016	63,661	$1,173	$19.45	$16.87 - $21.75
Q3 2016	121,666	$2,308	$18.15	$15.62 - $21.53
Q2 2016	105,239	$1,696	$14.11	$11.41 - $16.78
Q1 2016	31,317	$376	$11.79	$10.50 - $14.18
Q4 2015	31,317	$446	$13.21	$10.57 - $15.84
Q3 2015	39,017	$456	$15.00	$10.61 - $18.30