BIIB· Biogen

Dark pool · off-exchange short volume

as of 2026-11-05

BIIB's off-exchange short-volume ratio was 54.8% on 5 Nov 2026, below its 20-day average of 62.6%. Off-exchange trading was 39% of volume over the last 20 sessions. 15 sessions in the last six months had unusually large off-exchange dollar volume, the latest on 28 Oct 2026.

Short ratio (latest)

54.8%

20-day average

62.6%

Off-exchange share (20d)

39%

Darkpool density

big day, short ratio above trendbelow trendbubble size = how unusual ($vol z-score)

Last ~6 months. Bubbles mark days of unusually large off-exchange dollar volume (≥1.5σ vs the trailing 60 days). Daily resolution — not print-level data.

Darkpool levels ±15% of spot, since 2018-10-01

290.08

6.73B

285.00

7.92B

279.91

8.47B

274.82

6.63B

269.73

8.27B

264.64

6.93B

259.55

4.08B

254.46

2.81B

249.37

3.61B

244.28

4.52B

239.19

4.88B

234.10

8.75B

229.01

9.50B

223.92

7.96B

218.84

5.86B

Historical off-exchange $ volume at price: each day's volume spread across that day's range, summed over the full FINRA history. Heavy shelves often act as support/resistance magnets. Amber row = spot's bin.

Off-exchange short-volume ratio

short ratio (20d, right) daily off-exchange share (left)

FINRA daily TRF data, last 2 years. A persistently HIGH short ratio is mostly passive market-maker liquidity provision (commonly read as accumulation pressure) — not naively bearish.