Karol G’s “BbY WOW” with Judeline and rusowsky sits at a 94.9% implied probability for the top Spotify song the week of September 4 because the track has posted the strongest recent global streaming gains of any release. It reached No. 1 on Spotify’s daily global chart in late August with daily peaks above 3.6 million streams, displaced Karol G’s own prior single on the Billboard Hot Latin Songs chart, and logged multi-million U.S. streams in its first tracking weeks after the August album drop. The song’s danceable production and broad Latin-market dominance have sustained its lead. An upset would require a late-week surge from another track that closes a sizable streaming gap before the chart period ends.