Alters incorrect trading updates (6)
I believe the answer is:
alerts
'trading updates' is the definition.
(I've seen this in another clue)
'alters incorrect' is the wordplay.
'incorrect' is an anagram indicator.
'alters' anagrammed gives 'ALERTS'.
(Other definitions for alerts that I've seen before include "Alarms, warning signals" , "danger-signals" , "Warnings" , "Warns, draws attention to" , "Draws attention to, a danger perhaps" .)