SPY· SPDR S&P 500 ETF Trust
Dark pool · off-exchange short volume
Short ratio (latest)
56.2%
20-day average
53.9%
Off-exchange share (20d)
31%
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
752.94
285B
738.18
342B
723.42
81.3B
708.65
125B
693.89
276B
679.13
881B
664.36
549B
649.60
408B
634.83
312B
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.