Hikaru Nakamura is American Grandmaster. He is one of the 10 best players in classical chess for more than 3 years. He has the fame that he is the best bullet chess player in the world.
He took the golden medal in Baku chess olympiad as member of US national team playing in the 2nd board after Caruana Fabiano. He made 7.5/11 with a performance a little bit less than his actual rating but good enough to give to US team the golden medal.
His official twitter account is @GMHikaru