Robusta coffee traded in London bounced back from a three-day losing streak amid speculations that the fall of its prices gone too far after a drought that might reduce output of the variety bothering the world's largest producer Vietnam. May Robusta coffee futures advanced 0.7% to $2,167 a ton earlier on Thursday London session, while May Arabica coffee futures dropped 0.3% to $1.332 a pound in New York.