Sales do badly — stock so restricted? (7)
I believe the answer is:
lassoed
'stock so restricted?' is the definition.
(stock or cattle might be lassoed)
'sales do badly' is the wordplay.
'badly' indicates an anagram (letters in the wrong order).
'sales'+'do'='salesdo'
'salesdo' with letters rearranged gives 'LASSOED'.
(Other definitions for lassoed that I've seen before include "Roped livestock with a noose" , "Caught with a rope" , "as stock is restricted" .)