The year saw K-pop companies making mega moves on a global scale, while the catalog market remained hot.
Kakao chief investment officer Bae Jae-hyun is accused of inflating SM’s share price to thwart HYBE’s bid for a stake in the K-pop company earlier this year.
The Billboard Global Music Index fell 3.1% to 1,313.44, lowering its year-to-date gain to 12.5%.
The "integrated corporation" in the world's top music market is an expansion of SM and Kakao's existing partnership.
After losing its bid for a controlling stake in the K-pop agency to rival bidder Kakao, HYBE has struck a platform collaboration with its former target.
HYBE still owns an 8.8% stake in the competing K-pop company after Kakao purchased an additional 1.66 million of its shares.
The companies are wrestling for control of SM with competing board slates at the March 31 annual meeting in Seoul.
The announcement came a day after a court injunction forced Kakao to cancel its plan to acquire a 9.05% stake directly from SM.
HYBE also sends a letter to SM demanding the current board terminate a pact with Kakao and withdraw its Kakao-nominated director candidate.
HYBE, which owns a 14.8% stake in the competing K-pop company, criticized the tie-up with tech company Kakao as one-sided and harmful to shareholders.