Policy changed to invest millions — for such athletes? (7)
I believe the answer is:
olympic
'such athletes?' is the definition.
(as in Olympic athletes)
'policy changed to invest millions' is the wordplay.
'changed' indicates anagramming the letters.
'to invest' means one lot of letters goes inside another.
'millions' becomes 'm' (abbreviation).
'policy' is an anagram of 'olypic'.
'olypic' placed around 'm' is 'OLYMPIC'.
'for' acts as a link.
(Other definitions for olympic that I've seen before include "Relating to world games" , "of champion" , "Of Summer or Winter games" , "It may precede record" , "These games are held every four years" .)