Source of exchange rate unchanged? It’ll get attention (8)
I believe the answer is:
emphasis
'it'll get attention' is the definition.
(emphasis draws someone's attention to something)
'source of exchange rate unchanged?' is the wordplay.
'source of' suggests taking the first letters.
'rate' becomes 'mph' (miles per hour).
'unchanged?' becomes 'asis' (as things currently are).
The initial letter of 'exchange' is 'e'.
'e'+'mph'+'asis'='EMPHASIS'
(Other definitions for emphasis that I've seen before include "Weight" , "Special importance or prominence given to something" , "Stress, accent" , "Special importance or significance" , "Intensity of expression" .)