nosedive
noun [ C, usually singular ]
uk/ˈnəʊzdaɪv/ usa sudden fast fall in price, value, etc.:
Most analysts view the stock's recent nosedive as investor overreaction.
Shares on Wall Street took a nosedive last night.
nosedive
verb [ I ]
uk/ˈnəʊzdaɪv/ usto suddenly fall in value, quickly and by a large amount:
Market prices continue to nosedive this week.