The most common and most likely answer to this crossword clue is the 7 letter word UPTREND
I've seen this crossword clue in The Guardian
U
P
T
R
E
N
D
Buddy explains!

The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does UPTREND mean?
UPTREND noun- An upward trend, or an upturn.
- To undergo an upward trend.