Concealed stock ready for auditor (5)
I believe the answer is:
cache
'concealed stock' is the definition.
(a hidden reserve of something)
'ready for auditor' is the wordplay.
'ready' becomes 'cash' (I've seen this before).
'for auditor' shows a homophone (sound like).
'cash' is a homophone of 'CACHE'.
(Other definitions for cache that I've seen before include "(Place in) hidden store" , "Hiding-place for treasure etc" , "memory" , "Stockpile" , "Conceal" .)