Antonyms for the phrase "on the up up" include "on the decline," "in decline," "on the way down," "losing ground," "losing momentum" and "on the decrease." These words and phrases refer to situations in which progress, growth or improvement has stalled or reversed. They are often used to describe economic trends, political fortunes, sports teams, health conditions or personal relationships. By contrast, "on the up up" implies that things are going well, gaining momentum or improving over time. The phrase can be used to express optimism, confidence and encouragement in a range of contexts.