hit it big

Score a major success, especially a profit, as in Some investors hit it big in the stock market. The adverb big here means “with great success.” [Slang; late 1800s]

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.