Card player's net assets oddly going missing (4)
I believe the answer is:
east
'card player's' is the definition.
(bridge players are known by compass position)
'net assets oddly going missing' is the wordplay.
'oddly going missing' indicates alternate letters.
'net'+'assets'='netassets'
The alternate letters of 'netassets' are 'EAST'.
(Other definitions for east that I've seen before include "Chinese, perhaps" , "the way the Wise Men came from" , "Compass bearing" , "Player in deal" , "On most maps it's right!" .)