NASDAQ:AMPH | Historical Stock Price | Amphastar Pharmaceuticals, Inc.

Complete retained daily price history on its own workbook tab. Split-adjusted close keeps every historical share price on one comparable split basis. Cumulative dividend-reinvested close is the daily close of a rebased total-return index: it starts with one share at the earliest retained close, reinvests every distribution, and normalizes every forward and reverse split exactly once. Admitted exchange opening prices remain a distinct current-session series.

Available history
2014-06-25 to 2026-09-04
Data captured

Stock Price Chart

Blue: Split-adjusted close · Orange: Cumulative dividend-reinvested close

$8.31$12.59$19.07$28.88$43.73$66.232014-06-252026-08-27

Logarithmic scale. Both lines share the same starting value for the selected range.

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Historical Stock Price — 2018

DateSplit-adjusted closeCumulative dividend-reinvested closeReported volumeOpen priceExchange Volume
2018-12-31$19.90$19.90150,400
2018-12-28$20.04$20.04211,900
2018-12-27$19.96$19.96266,700
2018-12-26$19.82$19.82195,600
2018-12-24$19.04$19.04134,900
2018-12-21$19.64$19.64880,600
2018-12-20$20.08$20.08320,700
2018-12-19$20.74$20.74479,500
2018-12-18$19.94$19.94217,200
2018-12-17$20.04$20.04303,100
2018-12-14$20.32$20.32175,200
2018-12-13$20.90$20.90151,800
2018-12-12$21.11$21.11184,700
2018-12-11$21.25$21.25294,600
2018-12-10$22.00$22.00282,700
2018-12-07$21.99$21.99248,400
2018-12-06$21.72$21.72401,800
2018-12-04$21.47$21.471,232,100
2018-12-03$22.51$22.51746,600
2018-11-30$21.72$21.72663,700
2018-11-29$20.36$20.36133,800
2018-11-28$20.53$20.53193,200
2018-11-27$19.65$19.65156,100
2018-11-26$19.61$19.61167,900
2018-11-23$20.15$20.1562,200
2018-11-21$20.00$20.0098,900
2018-11-20$20.07$20.07164,900
2018-11-19$20.51$20.51195,800
2018-11-16$20.67$20.67510,700
2018-11-15$20.92$20.92200,700
2018-11-14$20.13$20.13224,200
2018-11-13$21.21$21.21267,100
2018-11-12$21.00$21.00242,200
2018-11-09$21.59$21.59735,300
2018-11-08$20.71$20.71842,400
2018-11-07$19.25$19.25144,300
2018-11-06$19.23$19.23144,200
2018-11-05$18.95$18.95135,600
2018-11-02$18.77$18.77149,100
2018-11-01$18.44$18.44144,000
2018-10-31$17.95$17.95117,600
2018-10-30$18.26$18.2689,700
2018-10-29$18.08$18.08100,500
2018-10-26$18.29$18.29114,600
2018-10-25$17.97$17.97107,300
2018-10-24$17.72$17.72113,600
2018-10-23$18.23$18.23141,100
2018-10-22$18.24$18.24120,300
2018-10-19$18.53$18.53119,200
2018-10-18$18.73$18.7377,500
2018-10-17$18.87$18.8783,900
2018-10-16$18.63$18.63110,100
2018-10-15$18.18$18.1877,900
2018-10-12$18.06$18.06132,500
2018-10-11$18.15$18.15130,200
2018-10-10$18.70$18.70128,200
2018-10-09$19.02$19.02128,600
2018-10-08$18.85$18.8582,000
2018-10-05$18.77$18.77135,200
2018-10-04$19.09$19.09102,600
2018-10-03$19.25$19.25164,800
2018-10-02$19.07$19.07152,200
2018-10-01$19.26$19.26246,900
2018-09-28$19.24$19.24169,200
2018-09-27$19.13$19.13120,400
2018-09-26$19.24$19.24238,500
2018-09-25$19.24$19.2469,100
2018-09-24$19.38$19.38104,400
2018-09-21$19.18$19.18586,700
2018-09-20$19.06$19.06123,900
2018-09-19$18.70$18.70123,400
2018-09-18$18.58$18.58144,000
2018-09-17$18.35$18.35142,700
2018-09-14$18.89$18.89159,100
2018-09-13$18.48$18.48143,200
2018-09-12$18.49$18.49164,700
2018-09-11$19.06$19.06161,500
2018-09-10$19.19$19.19108,200
2018-09-07$19.27$19.27164,000
2018-09-06$19.24$19.24182,500
2018-09-05$19.35$19.35231,300
2018-09-04$19.28$19.28244,600
2018-08-31$18.98$18.98298,900
2018-08-30$18.39$18.3984,700
2018-08-29$18.27$18.2769,600
2018-08-28$18.09$18.09100,600
2018-08-27$18.03$18.03100,700
2018-08-24$18.02$18.0294,000
2018-08-23$18.12$18.12112,300
2018-08-22$18.37$18.37178,200
2018-08-21$18.22$18.22195,200
2018-08-20$17.96$17.96139,700
2018-08-17$17.82$17.82116,000
2018-08-16$18.04$18.04175,600
2018-08-15$17.50$17.50129,200
2018-08-14$17.68$17.68105,600
2018-08-13$17.63$17.63159,500
2018-08-10$17.32$17.32147,300
2018-08-09$17.18$17.18341,900
2018-08-08$17.97$17.9797,600
2018-08-07$17.80$17.80130,200
2018-08-06$17.63$17.63125,300
2018-08-03$17.40$17.4098,300
2018-08-02$17.27$17.2778,600
2018-08-01$17.22$17.22120,800
2018-07-31$17.45$17.45139,000
2018-07-30$17.13$17.1377,100
2018-07-27$17.19$17.19121,300
2018-07-26$17.43$17.43133,600
2018-07-25$17.20$17.20139,700
2018-07-24$17.17$17.17142,000
2018-07-23$17.13$17.13139,000
2018-07-20$16.90$16.90143,700
2018-07-19$16.64$16.64161,400
2018-07-18$16.37$16.3798,700
2018-07-17$16.42$16.4285,500
2018-07-16$16.21$16.21121,000
2018-07-13$16.53$16.53228,900
2018-07-12$16.67$16.67190,400
2018-07-11$16.68$16.68160,100
2018-07-10$16.91$16.91166,400
2018-07-09$16.80$16.80158,900
2018-07-06$16.35$16.35102,600
2018-07-05$16.34$16.34184,400
2018-07-03$15.76$15.76164,000
2018-07-02$15.39$15.39326,100
2018-06-29$15.26$15.26249,900
2018-06-28$15.50$15.50107,000
2018-06-27$15.55$15.55170,900
2018-06-26$15.87$15.87150,800
2018-06-25$15.55$15.55238,400
2018-06-22$15.77$15.77995,800
2018-06-21$16.10$16.10236,600
2018-06-20$16.50$16.50319,800
2018-06-19$16.96$16.96234,200
2018-06-18$16.84$16.84152,100
2018-06-15$16.88$16.88293,100
2018-06-14$16.96$16.96173,000
2018-06-13$16.77$16.77135,600
2018-06-12$16.68$16.68149,100
2018-06-11$16.59$16.59197,800
2018-06-08$16.67$16.67169,200
2018-06-07$16.69$16.69109,600
2018-06-06$16.79$16.79251,900
2018-06-05$16.65$16.65171,100
2018-06-04$16.52$16.52284,900
2018-06-01$16.12$16.12193,800
2018-05-31$15.80$15.80324,400
2018-05-30$15.91$15.911,273,700
2018-05-29$16.10$16.10436,300
2018-05-25$16.00$16.00458,100
2018-05-24$16.56$16.56202,400
2018-05-23$16.59$16.59125,500
2018-05-22$16.64$16.64136,700
2018-05-21$16.57$16.57137,300
2018-05-18$16.63$16.63265,100
2018-05-17$16.22$16.22205,300
2018-05-16$16.00$16.00356,200
2018-05-15$15.57$15.57333,300
2018-05-14$16.12$16.12389,900
2018-05-11$14.91$14.91429,400
2018-05-10$14.63$14.631,181,600
2018-05-09$19.43$19.43137,500
2018-05-08$19.21$19.2179,600
2018-05-07$18.98$18.9882,400
2018-05-04$18.77$18.77102,300
2018-05-03$18.50$18.50136,600
2018-05-02$18.97$18.97104,600
2018-05-01$19.13$19.1379,000
2018-04-30$19.09$19.0974,400
2018-04-27$19.25$19.2566,000
2018-04-26$19.21$19.2148,900
2018-04-25$19.28$19.2866,600
2018-04-24$19.25$19.2570,000
2018-04-23$19.33$19.3381,300
2018-04-20$19.31$19.3169,600
2018-04-19$19.48$19.4857,300
2018-04-18$19.56$19.56119,800
2018-04-17$19.60$19.60177,300
2018-04-16$19.18$19.1874,500
2018-04-13$18.96$18.9683,300
2018-04-12$19.05$19.0591,400
2018-04-11$19.21$19.21115,900
2018-04-10$19.25$19.25123,800
2018-04-09$18.88$18.88114,000
2018-04-06$19.01$19.01157,700
2018-04-05$19.14$19.14148,000
2018-04-04$19.02$19.02193,200
2018-04-03$18.64$18.64165,400
2018-04-02$18.24$18.24222,800
2018-03-29$18.75$18.75156,500
2018-03-28$18.47$18.47215,200
2018-03-27$18.47$18.47190,900
2018-03-26$18.61$18.61213,800
2018-03-23$18.61$18.61229,500
2018-03-22$19.12$19.12196,200
2018-03-21$19.51$19.51113,700
2018-03-20$19.44$19.44162,000
2018-03-19$19.57$19.57321,200
2018-03-16$19.91$19.91393,400
2018-03-15$19.79$19.79282,500
2018-03-14$20.24$20.24349,600
2018-03-13$20.35$20.351,133,500
2018-03-12$19.58$19.58222,100
2018-03-09$19.14$19.14299,500
2018-03-08$18.80$18.80168,100
2018-03-07$18.30$18.30190,400
2018-03-06$17.93$17.93176,700
2018-03-05$18.13$18.13255,800
2018-03-02$18.34$18.34182,700
2018-03-01$18.06$18.06249,500
2018-02-28$18.36$18.36187,300
2018-02-27$19.04$19.04214,000
2018-02-26$19.18$19.18178,500
2018-02-23$19.20$19.20184,700
2018-02-22$18.84$18.84149,600
2018-02-21$18.73$18.73171,700
2018-02-20$18.42$18.42130,500
2018-02-16$18.78$18.78111,100
2018-02-15$19.03$19.03129,700
2018-02-14$18.76$18.76143,400
2018-02-13$18.41$18.41129,000
2018-02-12$18.50$18.50197,000
2018-02-09$18.40$18.40269,100
2018-02-08$17.85$17.85162,800
2018-02-07$17.94$17.94150,200
2018-02-06$17.54$17.54292,500
2018-02-05$17.23$17.23234,200
2018-02-02$18.37$18.37133,400
2018-02-01$18.94$18.94149,300
2018-01-31$18.64$18.64182,900
2018-01-30$18.92$18.92240,900
2018-01-29$19.59$19.59140,600
2018-01-26$19.58$19.58159,900
2018-01-25$19.40$19.4088,000
2018-01-24$19.32$19.32122,600
2018-01-23$19.39$19.3976,000
2018-01-22$19.37$19.37112,800
2018-01-19$19.37$19.37112,000
2018-01-18$19.46$19.46178,500
2018-01-17$19.45$19.45231,400
2018-01-16$18.78$18.78204,400
2018-01-12$18.56$18.56170,500
2018-01-11$18.16$18.16132,800
2018-01-10$17.82$17.82168,900
2018-01-09$17.92$17.92125,300
2018-01-08$18.03$18.03200,100
2018-01-05$18.06$18.06161,600
2018-01-04$18.28$18.28167,600
2018-01-03$18.77$18.77290,300
2018-01-02$19.17$19.17262,800