Noun
dark pool (plural dark pools)
(finance) A private forum for trading securities, derivatives, and other financial instruments.
Beware the dark pool at the bottom of our hearts. In its icy, black depths dwell strange and twisted creatures it is best not to disturb. Sue Grafton
Night had come-night that she loved of all times, night in which the reflections in the dark pool of the mind shine more clearly than by day. Virginia Woolf