(idiomatic) Rising; becoming greater in number or magnitude.
(sports) While the ball is rising.
Source: en.wiktionary.orgYour child's future was the first to go with budget cuts, if you think that hurts then wait here comes the upper-cut, the school was garbage in the first place that's on the up and up. Lupe Fiasco
It's kind of fun when you're playing characters that aren't quite on the up and up and people still like you. Kevin Nealon
Lot of things depend on the up bringing of a child. Shiv Khera
On the up in County Down: Worried about sudden quarantines on trips abroad? Source: Internet