The Gaon Chart is the national chart of South Korea and is intended to be the equivalent of Oricon in Japan and Billboard in the United States.
According to the Gaon Chart Physical Albums Rankings from January to September, the following are the rankings of the best-selling boy groups in 2021 thus far.
| Rank | Artist | Sales (Copies) |
| 1 | BTS | 6,263,329 |
| 2 | NCT Dream | 3,819,970 |
| 3 | NCT 127 | 2,690,943 |
| 4 | TXT | 1,837,400 |
| 5 | Stray Kids | 1,753,627 |
| 6 | Seventeen | 1,690,528 |
| 7 | EXO | 1,495,497 |
| 8 | ATEEZ | 1,417,574 |
| 9 | ENHYPEN | 882,750 |
| 10 | The Boyz | 787,685 |
All other groups made a single comeback this year except for NCT Dream, TXT, and ATEEZ who made 2 comebacks to date.
Netizens reacted: "BTS only released a single wow"
"BTS is on another level lol But I can see how much NCT has grown as an artist."
"I'm so proud of Stray Kids and TXT. Look how much they have grown. Some people were saying they are flops and are known only because of their labels. But look at those numbers. I'm rooting for both groups."
"BTS could easily hit 10M copies if they release another single damn"