I honestly would love to know why it didn't move like that any time before. I would have never thought I would see it moving like that at any point of her career.
The race is between Anaconda, Shake It Off, and All About That Bass. Each has has something on their side (airplay, streaming, and/or sales), but also something holding it back slightly. We won't know for sure who is taking the top spot until airplay, streaming, and sales figures are finalized.
It isn't a 75% chance Anaconda will swoop in and take the top spot, but it is still in the race.
What Nicki needs to do is drop something big at a time when there's no competition. She always get's blocked by monster smashes. I guess there was no way of knowing about Taylor's release tho.
Also, the treatment for Anaconda's release kind of shows she needs to let her label take the wheel more often. The fact that it took three eras to finally have a perfectly-executed single release. smh