Fast Money is played towards the end of a game where you have to answer 5 questions twice to ultimately end up with over 200 points to win the Jackpot. To earn this achievement, proceed through the Fast Money round until you are about to answer the 5th question for the second time, type in an answer and wait until there are less than 5 seconds remaining. As soon as the timer hits 4, press the corresponding button for your answer you typed in. Achievement unlocked!
Notes: You do not need to ultimately get over 200 points to win, you just have to finish the last answer with under 5 seconds left. This does not count if you simply let the timer expire, you have to actually enter something and answer with at least 1-4 seconds left.