Retired in Toulouse, D'Artagnan deals in financial products (6)
I believe the answer is:
trades
'deals in financial products' is the definition.
'trades' can be an answer for 'deals' ('trade' can be a synonym of 'deal'). I'm not sure about the 'in financial products' bit.
'retired in toulouse d'artagnan' is the wordplay.
'retired' shows that the letters should be reversed in order.
'in' indicates the answer is hidden within the clue.
'sedart' is hidden within 'toulouse dartagnan'.
'sedart' in reverse letter order is 'TRADES'.
Can you help me to learn more?
(Other definitions for trades that I've seen before include "Buys and sells shares" , "Swaps - winds" , "Exchanges, buys or sells" , "will give some folk a living" , "Stared (anag)" .)