all-time low

The lowest level ever before reached or attained. Economists are panicking after the stock market reached an all-time low on Saturday. Our cash reserves are at an all-time low. We're going to need to take on a loan if the company is going to survive. A: "Geez, you only scored 200 points on that level?" B: "Hey, that's an all-time low, and it only happened 'cause you were in here distracting me!"

all-time high (low)

A record achievement (or failure), never before surpassed. An Americanism from the early twentieth century, the term has been applied to matters economic (production), recreational (golf score), and numerous other areas.