This scene confirms what the narrative has hinted at on several occasions now, which is that Faisal’s death was the result of a suicide. That there were at least four suicides that happened in response to the Ponzi scheme’s collapse indirectly implicates Alkaitis in more deaths as well, though Alkaitis’s assertion that he didn’t
force these people to die is true, too: ultimately, the investors chose to remain oblivious to any red flags that might have appeared over the years, and chose to respond to the Ponzi scheme’s collapse by ending their own lives. Alkaitis’s anger at the ghosts might actually be anger at himself for not being able to rid himself of the guilt he feels for these investors’ deaths.