make a killing
US /meɪk ə ˈkɪlɪŋ/
UK /meɪk ə ˈkɪlɪŋ/

1.
大赚一笔, 发大财
to make a lot of money very quickly and easily
:
•
He made a killing in the stock market during the tech boom.
他在科技繁荣时期在股市上大赚了一笔。
•
They're hoping to make a killing by selling their startup.
他们希望通过出售他们的初创公司来大赚一笔。