Prosperous periods, yen showing rise (7)
I believe the answer is:
upsurge
'rise' is the definition.
(I've seen this in another clue)
'prosperous periods yen' is the wordplay.
'prosperous periods' becomes 'ups' (I've seen this in another clue).
'yen' becomes 'urge' (I've seen this before).
'ups'+'urge'='UPSURGE'
'showing' is the link.
(Other definitions for upsurge that I've seen before include "growth" , "A sudden rise, as in business" , "Rapid rise" , "Sudden large increase" , "A sudden rise as in fortunes" .)