Solo Leveling ends its story as of 30 December 2021, after about 3 years since its first publication in March 2018. Solo Leveling ends at 179 chapters, which may seem relatively low number, considering how many contemporary Japanese mangaka have much longer running series.
Nevertheless, that means the story has concluded for now, unless any plans for sequels or spin-offs crop up. As it were, plans for a (presumably mobile) game from Netmarble, as well as a film and drama adaptation have been discussed prior, though actual teasers have been scarce at best. That’s not even mentioning the anime that people have been hankering for, for at least two whole years, that remain either well hidden or simply non-existent. What’s tangible is that there will be soundtrack released for the manhwa come February 2022 (and still is not a confirmation for an anime).
If you’d like something right now, you can buy volumes of the series from Yen Press, while you wait for the adaptations. The official blurb:
Known as the the Weakest Hunter of All Mankind, E-rank hunter Jinwoo Sung’s contribution to raids amounts to trying not to get killed. Unfortunately, between his mother’s hospital bills, his sister’s tuition, and his own lack of job prospects, he has no choice but to continue to put his life on the line. So when an opportunity arises for a bigger payout, he takes it…only to come face-to-face with a being whose power outranks anything he’s ever seen! With the party leader missing an arm and the only healer a quivering mess, can Jinwoo somehow find them a way out?