I worked for Morgan Stanley in London almost a decade ago, they were a notch down from Goldman Sachs, and there I worked supporting analysts roughly 90-100 hours per week for the entire 6 week engagement (and occasionally this was 6 days per week). I only did 6 weeks, but this was absolutely normal for those in that department.
This isn't to say that the whole of the company do it, but some teams, some roles, some functions... they really do these hours.
PS: "Notch down"... there was an unwritten hierarchy, if you worked at one rung of the hierarchy then you were good for that rung and the rungs below but not the rung above. This can be translated as "if you could survive in Goldman Sachs you can survive anywhere" and "if you can survive Morgan Stanley then you can survive anywhere except Goldman Sachs". "Survive" isn't just hours, but also being shouted at, whipped to work at a certain level, the sexism/racism... as a programmer I built a reporting system and one of the reports constructed by the manager at Morgan Stanley was nicknamed "the baseball bat" as it formed the basis for ritual punishment and humiliation of low performing analysts and traders.