Hip-hop is undoubtedly the most consumed genre in the world right now. It was made even more evident this year. Drake essentially held down the top of the Billboard Hot 100 for the majority of the year, Cardi B became the first female rapper to have 2 number one hits under her belt, and Migos ties the Beatles for most amount of simultaneous Hot 100 entries among groups. So it should come as no surprise that hip-hop also led RIAA's 2018 Gold & Platinum list.
Drake had a big year in 2018 and his RIAA plaques are further proof. The rapper's single, "God's Plan" is the RIAA's Top Song of the year while Scorpion was among the top albums in the RIAA's 2018 Gold & Platinum list. Cardi B's debut album, Invasion of Privacy, Post Malone's Beerbongs & Bentleys and Migos' Culture II have been certified double platinum. Additionally, J. Cole's K.O.D, XXXTENTACION's ?, and Camila Cabello's Camila were also certified platinum. Kendrick Lamar's Black Panther: The Album and Lady Gaga and Bradley Cooper's A Star Is Born soundtrack was also certified platinum.
Clearly, hip-hop dominated pop music this year and it doesn't look like that will end up changing next year. The RIAA revealed that 2018 saw 33 albums and 151 songs became certified either gold or platinum within the past year. You could read more information on the RIAA's criteria -- including how merch bundles are counted -- here.