It seems like One Piece has no plans of stopping, breaking records after records. It has been reported by Mantan Web that One Piece has surpassed 490 million copies in circulation surpassing the highest selling comic Batman. Highest selling comic Batman has 460 million copies in circulation.
According to article shared by Mantan Web, One Piece has 400 million copies in circulation in Japan, and 90 million copies in circulation worldwide (57 countries)
It is crazy to think that One Piece is just 10 million copies away from making it half a billion (500 million) copies sold, Which is unheard of in comics and manga industry.
One Piece is manga series, written and illustrated by Eiichiro Oda. First chapter was released in 1997, since than more than 1000 chapters have been released. Anime adaptation has been produced by Toei Animation and One Piece anime is close to surpassing 1000 episodes.
One Piece tells the story of a boy named luffy. He has the ability to stretch himself like rubber. Luffy alongside his crew adventures in the ocean with a goal of becoming a pirate king one day
Source: Mantan Web