BIIB· Biogen
Dark pool · off-exchange short volume
Short ratio (latest)
62.5%
20-day average
62.2%
Off-exchange share (20d)
37%
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
247.55
2.89B
243.21
3.73B
238.86
3.97B
234.52
6.97B
230.18
7.65B
225.84
6.83B
221.49
5.13B
217.15
4.35B
212.81
3.13B
208.46
2.81B
204.12
3.62B
199.78
3.92B
195.43
3.30B
191.09
2.84B
186.75
2.52B
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.