Rated wrongly by right businessman (6)

I believe the answer is:

trader

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'businessman' is the definition.
(I've seen this in another clue)

I don't understand the remainder of the clue.

(Other definitions for trader that I've seen before include "One buys and sells" , "Dealer who buys and sells" , "He buys and sells goods" , "Tarred the dealer badly" , "Tarred like merchant" .)

I've seen this clue in The Daily Express and The Mirror.

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