“Double down” comes from blackjack, where you double your bet on a strong hand,...

https://www.bright-bookmarks.win/double-down-means-to-take-a-bigger-risk-expecting-a-bigger-reward-it-comes

“Double down” comes from blackjack, where you double your bet on a strong hand, doubling the risk and reward. Learners often mistake it for “doing twice as much” in general, but it’s really about committing more when you’re confident