rights offering has 1 distinct synonym spread across 1 of its 1 sense. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
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.
an offering of common stock to existing shareholders who hold subscription rights or pre-emptive rights that entitle them to buy newly issued shares at a discount from the price at which they will be offered to the public later
“the investment banker who handles a rights offering usually agrees to buy any shares not bought by shareholders”
Synonyms, antonyms and the broader and narrower relations for rights offering come from Princeton University’s WordNet. Full sources and licences.