In financial jargon, the term "STK BUY" usually refers to a stock purchase or buying shares in a company. Synonyms for this phrase often depend on the context or the industry. For instance, in the finance world, alternative terms like "equities purchase" or "stock acquisition" can be used. If the focus is on investing, one could use "stock investment" or "share buying". Additionally, synonyms like "share acquisition" or "buying securities" may be employed in legal or corporate settings. Overall, while the phrase "STK BUY" is commonly used, there are several synonyms available to convey the act of purchasing stocks or shares.