The most common and most likely answer to this crossword clue is the 11 letter word ARBITRAGERS
A
R
B
I
T
R
A
G
E
R
S
Buddy explains!
The straight part
We know that "stock market players" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case stock market players = arbitragers.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 ARBITRAGERS mean?
ARBITRAGERS noun- One who participates in arbitrage.