Engage in shrewd bargaining within the equine business, perhaps (5,5)
I believe the answer is:
horse trade
'engage in shrewd bargaining within' is the definition.
I can't judge whether this definition defines the answer.
'equine business perhaps' is the wordplay.
I cannot really see how this works, but
'equine' could be 'horse' (horse is a kind of equine) and 'horse' is found in the answer.
'business' could be 'trade' (trade is a kind of business) and 'trade' is found in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'the' is the link.
Can you help me to learn more?
(Another definition for horse trade that I've seen is " attempt to bargain".)