Nintendo announced today that Pokémon X and Y sold over 4 million copies between October 12th, 2013 and October 13th, 2013. In September, Grand Theft Auto 5 sold 12 million copies on the first day of its release.

Pokémon X and Pokémon Y Sell More Than 4 Million Units Worldwide In First Two Days

First Pokémon RPG for Nintendo 3DS Launches Simultaneously Around the World

REDMOND, Wash., Oct. 15, 2013 – On Saturday, Oct. 12, Pokémon X and Pokémon Y for Nintendo 3DS became the first set of games in franchise history to launch simultaneously worldwide. Nintendo reported today that the games combined to sell more than 4 million units across Japan, Europe* and The Americas on Saturday, Oct. 12, and Sunday, Oct. 13.

"The early response to Pokémon X and Pokémon Y not only reaffirms the ongoing passion of Pokémon fans, but also indicates that an entirely new generation of gamers is eager to experience the franchise for itself," said Nintendo President Satoru Iwata.

Since this was the first global launch in franchise history, there isn't an exact historical precedent for comparison. However, when combining and comparing regional data for previous launches, Pokémon X and Pokémon Y would be the fastest-selling Nintendo 3DS games of all time and are tracking ahead of the last Pokémon RPG titles, Pokémon Black 2 and Pokémon White 2, by more than 70 percent.

With more than 245 million** games sold worldwide, the Pokémon franchise continues to be one of the strongest brands in the history of video games. Since 2002, five sets of Pokémon titles have combined to exceed 10 million units sold to date worldwide, with three sets combining to surpass 15 million units.

*Data from Europe primarily covers Saturday, Oct. 12, as the great majority of retail outlets are closed on Sundays across Europe.

**Pokémon global sales are based on internal sales figures, and are current as of March 31, 2013.

Source: http://press.nintendo.com/articles.jsp?id=40736