The most common and most likely answer to this crossword clue is the 10 letter word ORIGINATOR
I've seen this crossword clue in Financial Times
O
R
I
G
I
N
A
T
O
R
More clues leading to the result ORIGINATOR
Buddy explains!
The straight part
We know that "founder" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case founder = originator.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 ORIGINATOR mean?
ORIGINATOR noun- Someone who originates, creates or founds something.