Spero Therapeutics is trading 5.36% up in pre-market at $1.18, but the reason for the gain remains unclear. - The October 14 close was $1.12; coverage found no new company-specific announcement. The latest release, an October 2 inducement-grant notice, was not an apparent catalyst. - Hotter-than-expected U.S. inflation has pressured broader markets, while weakness continues in Asia; neither directly explains the gain. - A market report says shares crossed below the 200-day moving average during Monday trading.