We take a call about silver speculation (8)
I believe the answer is:
wagering
'speculation' is the definition.
(thesaurus)
'we take a call about silver' is the wordplay.
'take' says to put letters next to each other.
'a call' becomes 'ring' (telephone call).
'about' is an insertion indicator.
'silver' becomes 'Ag' (Ag is the chemical symbol for silver).
'we'+'ring'='wering'
'wering' enclosing 'ag' is 'WAGERING'.
(Other definitions for wagering that I've seen before include "Betting" , "better operation" .)