Ask an adviser about your own sale
Tell us what you sold, roughly what the gain is and which state you file in, and we pass it to tax advisers who handle gains of that size. They reply with a written answer and what they would charge to deal with it.
Everything this site publishes is built from the US capital gains tax record, and every sentence in it is checkable against the authority's own page. We quote and cite; we do not advise, and a quotation is not a substitute for an adviser who knows your facts.