The most common and most likely answer to this crossword clue is the 9 letter word PROACTIVE
I've seen this crossword clue in Financial Times
P
R
O
A
C
T
I
V
E
Buddy explains!
The straight part
We know that "Taking the initiative" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case taking the initiative = proactive.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 PROACTIVE mean?
PROACTIVE adjective- Acting in advance to deal with an expected change or difficulty