Three Months Ended

Nine Months Ended

September 30,

2021

2020

2021

2020

(in thousands, except per share data)

Basic and dilutive numerator:

Net income attributable to Amphastar Pharmaceuticals, Inc.

$

29,548

$

3,919

$

42,356

$

7,676

Denominator:

Weighted-average shares outstanding — basic

48,022

47,496

47,758

46,886

Net effect of dilutive securities:

Incremental shares from equity awards

1,987

2,352

1,935

2,036

Weighted-average shares outstanding — diluted

50,009

49,848

49,693

48,922

Net income per share attributable to Amphastar Pharmaceuticals, Inc. stockholders — basic

$

0.62

$

0.08

$

0.89

$

0.16

Net income per share attributable to Amphastar Pharmaceuticals, Inc. stockholders — diluted

$

0.59

$

0.08

$

0.85

$

0.16