BIIB · Biogen Inc.

$222.53 +6.49 (+3.00%)

S&P 500 member Russell 1000 member Rebalance outlook locked

Market Cap

$31.99B

147.64M

Daily short-sale volume published by FINRA from its trade-reporting facilities. It measures how many shares were sold short each day as a share of total volume — a daily flow, not the total outstanding short position.

1M 3M 6M 1Y 5Y All

Short Volume

Date	Short Volume	Short Exempt	Total Volume	Short %
2026-09-01	164,826	248	270,605	60.9%
2026-08-31	133,701	12	221,231	60.4%
2026-08-28	120,406	1	170,843	70.5%
2026-08-27	137,221	40	182,711	75.1%
2026-08-26	207,337	0	254,815	81.4%
2026-08-25	127,646	96	214,867	59.4%
2026-08-24	118,602	27	220,221	53.9%
2026-08-21	128,332	600	262,528	48.9%
2026-08-20	150,804	1	307,969	49.0%
2026-08-19	143,202	0	279,202	51.3%
2026-08-18	170,957	0	287,245	59.5%
2026-08-17	130,239	406	224,826	57.9%
2026-08-14	111,700	0	187,952	59.4%
2026-08-13	176,913	1	327,651	54.0%
2026-08-12	178,874	101	293,644	60.9%
2026-08-11	183,210	310	362,621	50.5%
2026-08-10	142,525	278	272,760	52.3%
2026-08-07	161,838	21,142	290,827	55.6%
2026-08-06	134,529	138	344,248	39.1%
2026-08-05	181,698	49	330,281	55.0%
2026-08-04	224,305	22	564,027	39.8%
2026-08-03	157,833	73	337,865	46.7%
2026-07-31	210,088	40	466,166	45.1%
2026-07-30	270,057	0	383,720	70.4%
2026-07-29	585,852	252	1,084,851	54.0%
2026-07-28	233,582	4	614,107	38.0%
2026-07-27	140,409	40	277,391	50.6%
2026-07-24	125,355	284	202,620	61.9%
2026-07-23	156,942	155	321,320	48.8%
2026-07-22	177,225	3	312,524	56.7%
2026-07-21	127,488	0	200,284	63.7%
2026-07-20	169,771	109	300,583	56.5%
2026-07-17	304,004	142	419,282	72.5%
2026-07-16	648,336	26	912,998	71.0%
2026-07-15	558,499	0	877,113	63.7%
2026-07-14	1,202,445	6,356	1,741,969	69.0%
2026-07-13	548,490	26	917,667	59.8%
2026-07-10	165,851	278	291,167	57.0%
2026-07-09	320,510	292	626,787	51.1%
2026-07-08	304,989	706	883,468	34.5%
2026-07-07	199,513	23	461,625	43.2%
2026-07-06	279,007	545	482,520	57.8%
2026-07-02	223,652	159	446,962	50.0%
2026-07-01	191,789	1,089	409,443	46.8%
2026-06-30	229,127	45	395,636	57.9%
2026-06-29	235,927	1,264	473,249	49.9%
2026-06-26	430,325	62	705,116	61.0%
2026-06-25	179,376	0	373,822	48.0%
2026-06-24	307,848	16,235	495,697	62.1%
2026-06-23	172,727	0	327,247	52.8%

Showing 1–50 of 64 days

Key facts CIK 875045 CUSIP 09062X103 13F (30d) 659 filings 648 filers Visit website Investor relations