For investment, one’s raised for example euros initially (5)
I believe the answer is:
siege
'for investment' is the definition.
(investment can mean a siege)
'one's raised for example euros initially' is the wordplay.
'one's' becomes 'i's' (Roman numeral).
'raised' is a reversal indicator (going up in a down clue).
'for example' becomes 'e.g.' (short for 'exempli gratia', 'for example' in Latin).
'initially' suggests taking the first letters.
The first letter of 'euros' is 'e'.
'is' in reverse letter order is 'si'.
'si'+'eg'+'e'='SIEGE'
(Other definitions for siege that I've seen before include "Military encirclement" , "Blockade of a town or fortress" , "Military operation ringing a town" , "Military blockade" , "seat" .)