Short summary concerning capital investment (5)
I believe the answer is:
recap
'short summary' is the definition.
(I've seen this in another clue)
'concerning capital investment' is the wordplay.
I cannot really understand how this works, but
'concerning' could be 're' (both can mean on a particular topic) and 're' is found in the answer.
'capital' could be 'cap' (synonyms) and 'cap' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for recap that I've seen before include "In brief, say it again" , "Review" , "Retrospective summary" , "Go over again with backward pacer" , "Final summary" .)