The Anatomy of a K-Pop Sleeper Hit: How CORTIS's 'GO!' Became a Viral Sensation
BIGHIT MUSIC's rookie group CORTIS is experiencing a 'yeokjuhaeng' (chart reversal) with their intro track 'GO!'. Learn how a viral fan video and incredible performances turned this B-side into a #1 hit.
In K-pop, the title track is usually the star of the show. But every so often, a B-side defies the odds and becomes a massive hit on its own. This is the story of CORTIS, BIGHIT MUSIC’s monster rookies, and how their debut intro track, “GO!,” became a viral sensation through a phenomenon known as “yeokjuhaeng.”
What is ‘Yeokjuhaeng’?
For international fans, yeokjuhaeng (역주행) is a key term to know. It literally means “reverse run” and describes when a song unexpectedly climbs back up the charts long after its initial release. It’s the K-pop equivalent of a “sleeper hit,” often sparked by a viral fan cam or a sudden wave of public interest, just like EXID’s “Up & Down” or Brave Girls’ “Rollin’.”
And now, CORTIS’s “GO!” has joined the ranks of these legendary chart reversals.
The Unlikely Rise of “GO!”
When CORTIS—a five-member “young creator crew” composed of Martin, James, Joohun, Seonghyun, and Gunho—debuted, their official title track was “What You Want.” But it was the album’s intro, “GO!,” that started to gain organic traction.
The group performed “GO!” for just one week on music shows. Those few powerful stages were all it took. Fan-edited videos compiling their performances went viral on social media, sparking a dance challenge craze. Viewers were captivated by the members’ raw talent, stable live vocals, and the song’s infectious energy.
The demand became undeniable. The song was “re-summoned” for a special performance on SBS’s Inkigayo, and a “Relay Dance” video on M2 gave fans an even better look at the choreography. This fan-driven movement sent the song flying up the charts.
A Chart-Topping Phenomenon
The results of this yeokjuhaeng have been staggering:
- Apple Music Korea: “GO!” climbed from an initial rank of #81 to #1 on the ‘Today’s Top 100’ chart.
- Melon: It became the only song by a 2025 rookie boy group to enter the Melon Daily Chart.
- Spotify: The track is maintaining over 1 million daily streams, with its numbers continuing to rise—a clear sign of genuine viral growth.
In an incredible show of the album’s overall strength, other tracks like “FaSHioN” and the title track “What You Want” have also joined “GO!” in the Top 10.
In response to the overwhelming support, BIGHIT MUSIC announced that CORTIS will perform “GO!” on more music shows this week as a special gift to the fans who made it all happen.
CORTIS’s success with “GO!” is a powerful reminder that in K-pop, a great song and a killer performance can create a hit at any time, proving that true talent will always find its way to the top.