There isn't much movement inside the Top Ten at the Pop format this week, but there is a battle looming between four big stars who all have incredible momentum on their songs. The Weeknd's "The Hills" (XO/Republic) takes a huge jump into Top 10 this week, vying for Greatest Gainer along with Taylor Swift's "Wildest Dreams" (Big Machine), already inside the Top 15 after two weeks. Justin Bieber's "What Do You Mean?" (RBMG/Def Jam) leaps into the Top 15 right behind Swift, while Macklemore & Ryan Lewis' "Downtown" (Macklemore/Warner Bros.) moves Top 20. All four superstar tracks are blowing up the chart with major spin explosions, so we expect they'll be shoving each other out of the way for position inside the Top Ten in no time!