Second only to sudden bereavement – Joan Aiken
一攫千金
i-.kkaku.sen.kin
Literally: one – take – thousand – gold
Alternately: Making a large profit at one stroke without much effort. Note that the instantaneous and easy nature of the wealth in question means that this phrase can’t be applied to even a great fortune if it was earned through steady effort.
Notes: This is a compound of compounds; 一攫 refers to “a single handful,” while 千金 indicates “a large amount of money.”
Replacing 攫 with homophone 穫 (“harvest”) is considered an error, but homophone 獲 (“to get,” “to earn”) is acceptable. Another variant replaces 千 with 万 (ban), “ten thousand.”
This phrase is attributed to our friend the Records of the Grand Historian (Japanese 『史記』 = Shiki).

Found in the title of a live-action adaptation of the gambling-centered manga 『賭博覇王伝 零』 = Tobaku haouden Zero, a.k.a. Gambling Emperor Legend Zero