Did you know that more than half of the artists currently ranking in the Top 10 on the Billboard World Albums Chart are K-pop acts? Naturally, the list includes extremely popular group BTS and their member J-Hope’s mixtape, Hope World, but as of April 2018, there are four other groups charting in the Top 10 right alongside them: Monsta X, TVXQ!, Stray Kids and NCT.

But just who are these K-pop acts dominating the charts? And what makes them so popular? Below, learn more about the K-pop artists and groups currently blowing up on Billboard.

  • Monsta X

    Monsta X is a group as fierce as their name. Formed through the survival television program NO.MERCY, Starship Entertainment trainees battled each other to become part of Monsta X. (Jooheon, Shownu, Wonho, Minhyuk, I.M, Hyungwon and Kihyun were the seven victorious members.)

    Monsta X debuted in 2015 with their single “Trespass,” and have since released multiple albums, filmed several television shows, and were nominated for a Teen Choice Award in 2017. Last year, the group embarked on their first world tour and visited eleven countries, including the U.S. This July, fans can witness them in concert as they return to six North American cities as part of their second world tour.

    Monsta X is known for having a masculine image, which is frequently seen in their music videos. Their most recent single, “Jealousy,” is a prime example of that concept: the song’s lyrics describe being in love to the point of obsession, constantly jealous of everyone who hangs out with their crush. Featuring a fiery rap written by members Jooheon and I.M, “Jealousy” is a unique combination of R&B and trap that highlights the dangerously seductive side of Monsta X.

  • TVXQ!

    TVXQ!’s career spans fifteen years, with over 14 million physical records sold (not including downloads), nine Korean albums, eight Japanese albums and five world tours. Their name translates to “Rising Gods of the East,” and they are one of the most influential K-pop groups to spread the Hallyu wave worldwide.

    Originally a five member group, three members of TVXQ! left SM Entertainment in 2010. The remaining members, U-Know Yunho and Max Changmin, have continued releasing music under the name TVXQ! as a duo.

    Almost every international K-pop fan has heard their 2008 single “Mirotic”—the song is considered one of the most popular songs in K-pop history and continues to inspire covers even today. In fact, the album the song was on was so popular that it broke a first-week album sale record by selling over 110,000 copies, ultimately becoming the best-selling album of 2008 and winning Album of the Year… twice.

    Following a two year hiatus while the members completed their mandatory military service, TVXQ! returned with their eighth studio album, New Chapter #1: The Chance of Love, in 2018. The first single, “The Chance of Love”—a jazz-swing dance track about being fated to fall in love with someone—showcases the pair’s next level vocals, choreography and style.

  • Stray Kids

    Stray Kids are the newest group on the list, though they’ve been in the spotlight since 2017. Similar to Monsta X, Stray Kids were formed on a reality TV program. However, instead of battling each other, the members worked together to prove they were ready to debut under JYP Entertainment.

    The group has nine members ranging in age from 17 to 21: Bang Chan, Woojin, Lee Know, Changbin, Hyunjin, Han, Felix, Seungmin and I.N. But don’t let their youth fool you—members Bang Chan, Changbin and Han write and arrange all of Stray Kids’ music and lyrics under the name 3RACHA, including their debut single, “District 9.”

    “District 9” is an explosive blend of EDM, hip-hop and rock that sends a bold call-to-action to misunderstood youth around the world. In the song’s lyrics, the members describe facing judgement in the world and urge listeners who feel slighted to unite with them: “Stray kids everywhere all around the world / Don’t wander around, get yourself over here.”

    The music video for “District 9” received 4,274,649 views in 24 hours, making it the most watched K-Pop debut music video in history.

  • NCT

    NCT is a group unlike any other. Formed under SM Entertainment, NCT aim to be a global brand with rotating members and multiple sub-units performing all over the world. Simply put: they’re limitless.

    Currently, NCT has four sub-units: NCT U, NCT 127, NCT Dream and NCT 2018. The full lineup consists of eighteen members: Lucas, Taeyong, Jungwoo, Jaehyun, Ten, Johnny, Taeil, Yuta, Mark, Haechan, Kun, Jaemin, Jeno, Renjun, Chenle, Jisung, Winwin, and Doyoung. A group as global as their dreams, members hail from the U.S., Canada, China, Hong Kong, Thailand, Japan and South Korea, representing a total of six different languages.

    Their first group, NCT U, debuted in 2016 with the hip-hop inspired “The 7th Sense” and rock ballad “WITHOUT YOU.” A rotational group, NCT U has no set members. As a result, it is more experimental in style, sound, and lineup.

    NCT 127 is Seoul’s representative unit who are known for their strong rap skills, showcased on tracks like “Cherry Bomb.” NCT Dream consists of the group’s youngest members, ranging from ages 16 to 18, who perform cuter, youthful songs like “Chewing Gum.”

    Meanwhile, NCT 2018 contains all 18 members. Their new album NCT 2018: Empathy, released March 14, features a collection of songs from each active unit. The album is considered a yearbook and chronicles all of the members who participated in NCT in 2018. (NCT will release a new yearbook annually.)

    The first track released from NCT 2018: Empathy was NCT U’s contribution, “BOSS.” The song is an urban, hip-hop track with a thick bassline and an addicting chorus. Filmed in the Ukraine, the music video depicts seven bosses who meet and decide to work together instead of fighting.