BIIB

Dark pool — off-exchange short volume

GEX Back to dark pool

Short ratio (latest)

73.8%

20-day average

63.1%

Off-exchange share (20d)

40%

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

222.98

5.02B

219.07

3.68B

215.16

2.52B

211.25

2.08B

207.34

1.77B

203.42

2.51B

199.51

2.55B

195.60

2.51B

191.69

2.41B

187.78

2.19B

183.86

2.56B

179.95

2.08B

176.04

2.48B

172.13

2.34B

168.22

1.16B

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.