October is actually a very busy school month, a lot of midterms/exams happen around this time. I think people just weren't all that impressed with what was available and maybe just decided to be productive instead of going to the movies. There's no real franchise films. The star power movies mostly tanked with critics/WOM (Burnt, Our Brand is Crisis, Witch Hunter, Pan), the well-reviewed films had actors no one cared about (Steve Jobs, The Walk, Crimson Peak), then there's the films that tanked with critics and also had no one famous (all the other ones). The only ones that had both star power and great reviews were The Martian, a huge hit, and the leggy sleeper hit Bridge of Spies. So yeah, great month for Saving Private Ryan alums (lol oh wait except Vin Diesel I guess).