In reverse of normality, a bear market with ever-rising prices (4)
I believe the answer is:
ebay
'market with ever-rising prices' is the definition.
(auction website)
'in reverse of normality a bear' is the wordplay.
'in reverse' says the letters should be written backwards.
'of' indicates a hidden word.
'yabe' can be found hidden inside 'normality a bear'.
'yabe' back-to-front is 'EBAY'.
(Other definitions for ebay that I've seen before include "Modern marketplace" , "Online selling site" , "Electronic marketplace" , "Online marketplace" , "Auction site" .)