The phrase "took stock in" refers to the act of investing time, effort or money into something. Some antonyms for this expression include ignoring, disregarding, neglecting, or dismissing. Ignoring implies a lack of attention given to something, disregarding means refusing to acknowledge its importance, neglecting suggests a failure to care for or oversee, and dismissing indicates a deliberate rejection of something's value or relevance. Therefore, if you want to express the opposite of 'taking stock in' something, you could use any of these antonyms to convey a sense of neglect, indifference or rejection towards it.