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A Year After the Account Opened, 15 Million
CORTIS’s official Instagram account passed 15 million followers on August 5. Big Hit Music, the group’s agency, announced the milestone on August 8, calling it the fastest such record among K-pop groups that have debuted in the past five years. The account reached the mark roughly a year after it was created.
According to Big Hit Music, as of the morning of August 8, CORTIS had 15.82 million TikTok followers and 6.24 million YouTube subscribers — the highest YouTube subscriber count among K-pop boy groups that debuted within the last five years. In other words, the growth isn’t concentrated on a single platform.
CORTIS is a five-member group that debuted on August 18, 2025, with the single “What You Want.” The lineup — Martin, James, Juhoon, Sunghyun and Gunho — marks Big Hit Music’s first new group in six years, following BTS and Tomorrow X Together.
Why This Number Is Unusual
Fifteen million followers isn’t, on its own, an unprecedented number in K-pop. But the groups that have reached that level have mostly spent years releasing albums and touring the world to build up their fandoms. CORTIS is a first-year act, and its account is barely a year old. That means the same growth has been compressed into a fraction of the usual timeline.
The real story here isn’t the absolute figure of 15 million but how quickly the group got there. That’s why the agency qualified its claim as “fastest among groups debuted in the past five years” — it’s a record that only makes sense once you narrow the comparison to fellow newcomers.
That’s also why senior groups that debuted before 2020 are excluded from the comparison. Those acts started out under a different social media landscape — different user bases, different algorithms — and have had far longer to accumulate their numbers. Matching conditions before comparing growth rates among newer acts is the industry’s standard approach.
The Turning Point Lollapalooza Chicago Created
The turning point is widely pointed to as CORTIS’s set at Lollapalooza Chicago 2026, held at Grant Park on August 1. The group opened the T-Mobile Stage that day in front of roughly 50,000 people — their first Lollapalooza appearance since debuting.
Lollapalooza is a major four-day outdoor music festival held in Chicago every summer. Unlike a solo idol concert, a large share of its audience are general music fans there for the festival itself rather than for any one act — making it one of the rare stages that puts a group in front of an audience beyond its existing fandom.
According to the agency, footage of the performance and reactions to the group’s live vocals spread quickly on social media, drawing in new fans. That the follower count crossed 15 million four days after the show, on August 5, supports that reading. Still, the causal link between the two data points is difficult for outside observers to verify precisely.
The Chart Numbers Were Already Building Before That
One performance doesn’t explain everything, though. The title track “REDRED,” from CORTIS’s second mini album “GREENGREEN,” has stayed on Spotify’s Weekly Top Songs Global chart for 15 consecutive weeks. Over the same stretch it held the No. 1 spot on the Weekly Top Songs Korea chart — staying at the top domestically while also charting globally.
The song also stayed on Billboard’s Global 200 and Global Excl. U.S. charts for 14 consecutive weeks — not a brief spike right after release, but a trend that carried on for months. In other words, CORTIS’s music was already showing up consistently on global charts well before the Lollapalooza set.
Seen this way, Lollapalooza looks less like the cause of the growth and more like the moment that cashed in awareness the group had already built. Without that set, the pace of reaching 15 million would likely have been different — but it’s also hard to credit the number to a single show. That the agency mentioned the performance alongside the milestone as background, rather than as the sole cause, fits that reading.
What’s Left to Ask: The Distance Between Followers and Fandom
A follower count measures the total volume of attention, not the total volume of spending. How many of the 15 million people following the account will turn into core fans who buy albums and show up at concerts is still unknown — and the agency hasn’t released separate figures on that question.
Still, there’s something to read even in the numbers that have been released. CORTIS’s TikTok following (15.82 million) is larger than its Instagram following (15 million), and more than double its YouTube subscriber count (6.24 million) — a pattern that suggests attention that first spread on short-video platforms may still be migrating to other channels.
What’s ultimately worth watching are indicators like initial sales for the next album and how well a solo concert sells out. Whether the 15-million figure reflects the size of a fandom or the size of a passing wave of buzz should become clearer at that point. How CORTIS carries this record into its second year is the next thing to watch.
Source: Gibaek Yoon, Edaily, August 8, 2026.
