Hybrid Theory is the debut album by the American rock band Linkin Park, released on October 24, 2000 through Warner Bros. Records. The album was a huge commercial success, selling over 10 million units in the United States alone and peaking at number two on the Billboard 200 while also reaching high positions on other charts worldwide, despite receiving mixed reviews from publications. It has also sold 24 million copies worldwide as of 2009, including over 10 million in the U.S. which makes it the band's best-selling album, the second best-selling album of the 21st century so far, and the second best selling debut album. It is also one of the few albums to be certified Diamond in the U.S. that was released in this century.