Stella Lefty’s “Boston” holds a near-certain 99.5% implied probability for the Billboard Hot 100’s #2 spot the week of September 26 because of its commanding combination of streaming volume, radio airplay, and sales data that have kept it positioned just behind the current leader. Traders see little realistic path for an upset from the field of 50% outcomes or lower-probability tracks such as Ella Langley cuts, Taylor Swift’s “I Knew It, I Knew You,” or Morgan Wallen’s “Been By Now,” given the absence of comparable momentum or late-week surges. The chart locks in the coming days, so any surprise would require an unusually strong final tracking period or a sudden promotional push that has not yet materialized.