Dark-pool levels
Dark pool trading happens on venues that do not display orders before they execute.
Blocks and dark pool trades
A block is a large single trade of shares, on or off exchange. The two overlap, since many blocks trade off-exchange. Screens label them differently, but both are prints reported after the fact, not orders still waiting.
Fill labels on large prints
Large off-exchange prints are often labelled by where they traded against the quote: at the bid, at the ask, or no match. At the ask hints at a buyer in a hurry, at the bid a seller. No match means it printed between or away from the quote and is ambiguous. A block can also be one leg of a hedge.
Float proportion
Some block alerts show the print as a share of the float, the shares available to trade. The same dollar print can be tiny for a large company and meaningful for a thinly traded small one. Compare the print with typical daily volume and float, not with the dollar figure alone.
Off-exchange levels on a chart
Each print draws as a dashed horizontal rule across the plot with its own pill at the right edge: size, price and date. It is dashed so it can never be mistaken for a solid Ceiling or Floor rule.
- A brighter, heavier rule also printed today.
- A fainter, thinner one last printed on an earlier day inside the window, which is why it can sit at a price today never reached.
What a print does not tell you
No single field says why the trade was made. A level is a reference point, not a destination.