By May 06, 2021 Goodbye, the first quarter of 2021, hello second quarter! As we progress through the year, let us take a look back at the amazing drops that have happened this year so far. Want to know who the best-selling K-pop girl groups of this year so far are? Then keep reading! ITZY is the Best-Selling Girl Group of 2021 So Far Sitting at number one is JYP Entertainment's latest K-pop girl group, ITZY! Though they have only had one comeback this year, they managed to climb up the ranks! On Apr. 30, ITZY made a comeback with their fourth extended play, "Guess Who." ITZY has reportedly sold 257,857 copies of their albums so far.