The case for a range of investments (9)
I believe the answer is:
portfolio
I believe this is a double definition.
'the case' is the first definition.
(portfolio is a kind of case)
'a range of investments' is the second definition.
(I've seen this before)
'for' acts as a link.
(Other definitions for portfolio that I've seen before include "Range of investments" , "Set of investments held by one person" , "artist's sample work" , "Large case" , "Collection of papers" .)