Ton 618 is one of the most massive known black holes in the universe. It resides in the center of a distant galaxy and is estimated to have a mass of approximately 66 billion times that of the Sun. While Ton 618 is indeed a remarkably massive black hole, it is worth noting that the exact mass of black holes can be challenging to determine accurately, and new discoveries could potentially reveal even more massive black holes in the future.
Ton 618 was considered one of the most massive black holes known. However, it is possible that there may be larger black holes yet to be discovered. Astronomers continue to study the universe and make new observations, so it is always possible that future discoveries could unveil even more massive black holes. Therefore, it's important to keep in mind that our understanding of the universe is continuously evolving as new information becomes available.