WordNet records no synonym and no antonym for stocks. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a frame that supports a boat while it is under construction
a frame for constraining an animal while it is receiving veterinary attention or while being shod
a former instrument of punishment consisting of a heavy timber frame with holes in which the feet (and sometimes the hands) of an offender could be locked
Synonyms, antonyms and the broader and narrower relations for stocks come from Princeton University’s WordNet. Full sources and licences.