NASDAQ:IONS | Historical Stock Price | IONIS 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
1991-05-17 to 2026-09-04
Data captured

Stock Price Chart

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

$2.77$5.54$11.08$22.15$44.28$88.501991-05-172026-08-27

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

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Historical Stock Price — 1999

DateSplit-adjusted closeCumulative dividend-reinvested closeReported volumeOpen priceExchange Volume
1999-12-31$6.25$6.25534,400
1999-12-30$5.69$5.691,070,100
1999-12-29$6.97$6.972,477,300
1999-12-28$5.13$5.13775,400
1999-12-27$5.09$5.09665,300
1999-12-23$5.25$5.251,043,500
1999-12-22$5.03$5.031,318,300
1999-12-21$5.13$5.131,372,200
1999-12-20$5.50$5.501,304,200
1999-12-17$5.88$5.881,385,300
1999-12-16$6.19$6.194,916,900
1999-12-15$5.59$5.597,077,700
1999-12-14$15.50$15.50286,400
1999-12-13$15.06$15.06253,900
1999-12-10$14.88$14.88870,900
1999-12-09$15.50$15.50190,200
1999-12-08$15.81$15.81368,700
1999-12-07$15.00$15.00156,100
1999-12-06$15.50$15.50231,200
1999-12-03$15.56$15.56314,800
1999-12-02$16.13$16.13438,000
1999-12-01$15.25$15.25287,600
1999-11-30$15.63$15.63520,800
1999-11-29$16.00$16.001,357,800
1999-11-26$15.25$15.25163,000
1999-11-24$14.88$14.88211,800
1999-11-23$14.25$14.25636,200
1999-11-22$14.38$14.38299,700
1999-11-19$14.19$14.19454,300
1999-11-18$14.94$14.94738,200
1999-11-17$13.94$13.94420,700
1999-11-16$13.06$13.06676,000
1999-11-15$11.94$11.941,108,800
1999-11-12$12.94$12.94344,700
1999-11-11$13.06$13.06178,600
1999-11-10$13.00$13.00351,700
1999-11-09$12.56$12.56260,900
1999-11-08$12.31$12.31205,200
1999-11-05$12.44$12.44180,600
1999-11-04$12.69$12.69212,000
1999-11-03$11.81$11.81170,300
1999-11-02$11.75$11.75302,500
1999-11-01$11.56$11.56147,100
1999-10-29$11.56$11.56178,000
1999-10-28$11.56$11.56227,300
1999-10-27$11.31$11.31287,600
1999-10-26$11.94$11.94344,300
1999-10-25$12.00$12.00279,300
1999-10-22$11.88$11.88196,300
1999-10-21$11.88$11.88349,100
1999-10-20$12.50$12.50196,200
1999-10-19$12.44$12.44185,300
1999-10-18$12.06$12.06227,800
1999-10-15$12.38$12.38238,100
1999-10-14$13.25$13.25277,300
1999-10-13$14.06$14.06252,400
1999-10-12$14.75$14.75556,200
1999-10-11$15.13$15.13958,300
1999-10-08$13.06$13.06193,000
1999-10-07$11.75$11.7553,600
1999-10-06$11.63$11.6341,600
1999-10-05$11.50$11.5080,300
1999-10-04$11.44$11.4485,500
1999-10-01$11.56$11.56130,500
1999-09-30$11.19$11.19128,400
1999-09-29$11.94$11.9482,800
1999-09-28$11.63$11.63157,700
1999-09-27$12.06$12.06183,200
1999-09-24$12.00$12.00145,000
1999-09-23$12.25$12.25130,400
1999-09-22$12.06$12.0695,500
1999-09-21$12.19$12.19125,900
1999-09-20$12.06$12.06176,600
1999-09-17$12.38$12.38206,500
1999-09-16$12.25$12.25327,800
1999-09-15$12.50$12.50308,300
1999-09-14$12.81$12.81304,300
1999-09-13$12.88$12.88480,000
1999-09-10$13.13$13.13450,300
1999-09-09$12.88$12.88671,300
1999-09-08$11.69$11.69373,800
1999-09-07$11.25$11.25290,800
1999-09-03$11.00$11.00451,900
1999-09-02$11.44$11.44705,100
1999-09-01$10.06$10.06167,200
1999-08-31$10.13$10.1360,500
1999-08-30$10.06$10.0676,000
1999-08-27$10.25$10.25142,500
1999-08-26$9.88$9.8891,500
1999-08-25$10.19$10.19131,200
1999-08-24$10.13$10.13130,300
1999-08-23$10.25$10.25167,700
1999-08-20$10.00$10.00121,900
1999-08-19$9.25$9.2599,700
1999-08-18$9.38$9.38143,600
1999-08-17$9.38$9.38158,800
1999-08-16$9.75$9.7557,400
1999-08-13$9.69$9.6984,700
1999-08-12$10.00$10.00113,000
1999-08-11$9.63$9.63113,900
1999-08-10$9.63$9.63134,000
1999-08-09$9.69$9.6965,800
1999-08-06$9.50$9.50134,600
1999-08-05$9.94$9.94148,200
1999-08-04$9.84$9.84235,300
1999-08-03$9.81$9.81103,700
1999-08-02$10.38$10.38138,300
1999-07-30$10.38$10.38624,000
1999-07-29$10.00$10.00245,400
1999-07-28$10.00$10.00257,500
1999-07-27$10.19$10.19111,100
1999-07-26$10.13$10.1398,800
1999-07-23$10.19$10.1964,000
1999-07-22$10.25$10.2596,100
1999-07-21$10.31$10.31177,600
1999-07-20$10.25$10.2595,600
1999-07-19$10.19$10.19109,400
1999-07-16$10.31$10.31198,200
1999-07-15$10.19$10.19327,800
1999-07-14$10.13$10.13126,300
1999-07-13$10.13$10.13149,700
1999-07-12$10.19$10.19126,000
1999-07-09$10.47$10.47244,800
1999-07-08$10.06$10.06148,200
1999-07-07$9.88$9.88167,400
1999-07-06$10.00$10.00165,900
1999-07-02$10.06$10.06148,700
1999-07-01$10.25$10.25100,700
1999-06-30$10.19$10.19118,300
1999-06-29$10.19$10.1981,500
1999-06-28$10.56$10.5685,200
1999-06-25$10.81$10.81217,800
1999-06-24$10.94$10.94132,100
1999-06-23$10.81$10.81162,800
1999-06-22$10.88$10.88121,000
1999-06-21$11.50$11.50320,800
1999-06-18$11.56$11.56572,100
1999-06-17$10.50$10.50607,400
1999-06-16$10.13$10.13199,500
1999-06-15$9.63$9.6367,300
1999-06-14$9.56$9.5658,100
1999-06-11$9.56$9.5640,900
1999-06-10$9.81$9.8138,100
1999-06-09$9.84$9.8448,000
1999-06-08$9.81$9.8183,600
1999-06-07$9.91$9.91128,900
1999-06-04$9.88$9.88319,900
1999-06-03$9.69$9.6983,800
1999-06-02$9.94$9.9446,900
1999-06-01$9.75$9.7548,800
1999-05-28$10.13$10.1371,700
1999-05-27$9.88$9.8866,700
1999-05-26$10.00$10.00139,000
1999-05-25$10.13$10.1386,900
1999-05-24$10.13$10.1387,500
1999-05-21$10.03$10.03131,300
1999-05-20$10.50$10.50126,200
1999-05-19$10.13$10.13127,100
1999-05-18$9.94$9.94108,700
1999-05-17$10.13$10.1382,700
1999-05-14$10.69$10.69152,200
1999-05-13$10.75$10.7593,100
1999-05-12$10.31$10.3163,300
1999-05-11$10.50$10.50123,600
1999-05-10$10.31$10.3177,200
1999-05-07$9.88$9.8866,700
1999-05-06$9.69$9.6989,500
1999-05-05$10.13$10.1378,800
1999-05-04$9.94$9.9498,000
1999-05-03$10.25$10.2562,800
1999-04-30$10.44$10.4461,200
1999-04-29$10.56$10.5650,600
1999-04-28$10.50$10.50107,900
1999-04-27$11.00$11.00114,000
1999-04-26$10.75$10.7587,200
1999-04-23$10.56$10.5662,100
1999-04-22$10.38$10.38273,600
1999-04-21$10.13$10.13108,300
1999-04-20$10.13$10.1387,700
1999-04-19$10.00$10.00152,700
1999-04-16$9.91$9.9199,400
1999-04-15$10.00$10.00110,800
1999-04-14$10.13$10.13219,600
1999-04-13$9.88$9.88198,400
1999-04-12$9.94$9.94119,700
1999-04-09$9.50$9.5083,400
1999-04-08$9.81$9.8193,400
1999-04-07$10.00$10.00104,300
1999-04-06$9.75$9.75151,600
1999-04-05$9.38$9.38146,200
1999-04-01$10.06$10.06159,500
1999-03-31$9.00$9.00391,200
1999-03-30$10.25$10.2598,700
1999-03-29$10.56$10.5674,200
1999-03-26$10.50$10.5066,500
1999-03-25$11.00$11.0089,700
1999-03-24$10.69$10.69107,800
1999-03-23$10.75$10.75118,500
1999-03-22$10.94$10.94314,200
1999-03-19$11.19$11.19112,200
1999-03-18$11.25$11.2574,800
1999-03-17$11.38$11.3888,800
1999-03-16$11.38$11.3880,900
1999-03-15$11.63$11.6394,900
1999-03-12$11.75$11.7546,000
1999-03-11$11.94$11.94106,100
1999-03-10$11.88$11.8896,200
1999-03-09$11.50$11.50213,700
1999-03-08$11.63$11.63188,500
1999-03-05$12.13$12.1374,000
1999-03-04$12.03$12.0397,500
1999-03-03$11.75$11.75100,300
1999-03-02$12.00$12.00131,900
1999-03-01$11.81$11.8187,600
1999-02-26$12.06$12.06128,500
1999-02-25$12.06$12.06235,900
1999-02-24$12.25$12.2596,100
1999-02-23$12.50$12.50231,500
1999-02-22$12.63$12.63318,800
1999-02-19$11.75$11.75117,400
1999-02-18$11.50$11.50626,400
1999-02-17$11.63$11.6383,100
1999-02-16$12.13$12.1350,300
1999-02-12$12.00$12.0048,900
1999-02-11$12.13$12.13102,500
1999-02-10$11.88$11.88110,100
1999-02-09$12.06$12.06106,800
1999-02-08$12.50$12.50174,700
1999-02-05$12.56$12.56143,400
1999-02-04$12.75$12.75178,400
1999-02-03$13.38$13.3895,100
1999-02-02$13.38$13.38221,900
1999-02-01$13.38$13.38160,700
1999-01-29$13.88$13.88251,500
1999-01-28$14.13$14.13184,400
1999-01-27$14.81$14.81132,600
1999-01-26$14.88$14.88241,500
1999-01-25$14.25$14.25144,900
1999-01-22$14.50$14.50122,000
1999-01-21$13.75$13.75145,700
1999-01-20$13.75$13.75168,500
1999-01-19$14.13$14.13227,400
1999-01-15$14.25$14.25126,500
1999-01-14$13.56$13.56121,700
1999-01-13$14.13$14.13181,500
1999-01-12$14.56$14.56210,700
1999-01-11$13.94$13.94199,600
1999-01-08$14.38$14.38200,400
1999-01-07$15.00$15.00375,900
1999-01-06$14.88$14.88531,700
1999-01-05$14.56$14.56432,400
1999-01-04$13.38$13.38215,100