I understand there is a lower limit to stability for a BH. Below this the BH rapidly evaporates? What I was interested in was whether there is an upper limit to its size. A limit where above this the BH would become unstable and explode or dissolve in some way? It seems to me that the universe is constantly changing. Energy continuously strives to achieve stability in constantly evolving structures. Is a black hole the final state? It seems to me that although the universe is expanding all matter is also contracting. Will the universe eventually be just black holes with cold empty space between. Or will eventually all matter, dark and normal, and all energy, dark and normal fall into one black hole?