Where there's many a skill in trading (4)
I believe the answer is:
mart
'where' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'there's many a skill in trading' is the wordplay.
'there's' is a charade indicator (letters next to each other).
'many' becomes 'M' (Roman numeral for a thousand).
'a skill in trading' becomes 'art' (I can't justify this - if you can you should give a lot more credence to this answer).
'm' put next to 'art' is 'MART'.
Can you help me to learn more?
(Other definitions for mart that I've seen before include "US shop; market" , "Take tram to market" , "Place" , "Trading centre" .)