Apparent to the horse trade it's fixed (3)
I believe the answer is:
set
'fixed' is the definition.
('set' can be a synonym of 'fixed')
'apparent to the horse trade' is the wordplay.
'SET' is hidden in amongst the letters.
However, I'm uncertain how this is indicated.
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for set that I've seen before include "Major unit of tennis match" , "Gel; group" , "Major division of tennis match" , "Group of things of the same kind that belong together" , "Hardened" .)