Simulations suggest the early universe helped black holes grow big, but not in the long run

At the heart of the Milky Way, just 27,000 light-years from Earth, there is a supermassive black hole with a mass of more than 4 million suns. Nearly all galaxies contain a supermassive black hole, and many of them are much more massive. The black hole in the elliptical galaxy M87 has a mass of 6.5 billion suns. The largest black holes are more than 40 billion solar masses. We know these monsters lurk in the cosmos, but how did they form?