Yes — probably not. Stephenson 2-18 is thought to be an enormous red supergiant, but stars of that type usually lose a lot of mass before they die, and the final remnant is often a neutron star or, if enough mass remains, a black hole. NASA notes that very massive stars can end as black holes, while less massive ones end as white dwarfs or neutron stars.

What decides the outcome

The key factor is the star’s core mass at collapse, not just how huge it looks on the outside. A star can start out extremely large and still end up too lightweight in its core to form a black hole.

For Stephenson 2-18 specifically

Because it is a red supergiant, the likely path is: it burns through fuel, collapses, and explodes or sheds mass before the core collapses. If the remaining core is massive enough, it could leave behind a black hole; if not, it would be a neutron star. The exact outcome is uncertain because these extreme stars are difficult to measure precisely.

Simple version

Think of it like this: being huge does not automatically mean “black hole.” What matters is how much mass the core still has when the star dies.

TL;DR: Stephenson 2-18 might become a black hole, but it is not guaranteed ; it depends on how much mass it loses before core collapse.