Young upwardly mobile professional person (6)
I believe the answer is:
yuppie
(Other definitions for yuppie that I've seen before include "Well-paid middle-class professional with a luxurious life style" , "Young upwardly-mobile person" , "up-and-coming businessman" , "Informally a young professional person" , "Young, upwardly mobile, professional person of the 1980s" .)