cockroach effect
n.— «It’s sort of like what they call the “cockroach effect” on the financial markets. Every time there’s “hints” of anything going wrong inside a company, everybody starts selling the company’s stock in a knee-jerk vote of “no confidence.” A sign of “bad news” (whether explicit or implicit) may very well be just “one cockroach” popping up at the surface, while underneath the surface is a whole colony of cockroaches and numerous deeper problems about the company in question.» —“String Theory by Press Release” by JC Not Even Wrong June 22, 2004. (source: Double-Tongued Dictionary)
Further reading
The Italian idiom far venire il latte alle ginocchia literally means “to make milk come to the knees.” Figuratively, it means “to be really boring.” It’s been suggested that the phrase refers to the tedious process of...
Emily in San Diego, California, reports her father’s side of the family has a word for the back of the knee: nicket. German speakers refer to that part of the body as the Kniekehle, from German words meaning “knee” and...