Bubbling Under Hot 100

Bubbling Under Hot 100 Singles (also known as Bubbling Under the Hot 100) is a chart published weekly by Billboard magazine in the United States. The chart lists the top songs that have not yet charted on the main Billboard Hot 100. Chart rankings are based on radio airplay, sales, and streams. In its initial years, the chart listed 15 positions, but expanded to as many as 36 during the 1960s, particularly during years when over 700 singles made the Billboard Hot 100 chart. From 1974 to 1985, the chart consisted of 10 positions; since 1992, the Bubbling Under Hot 100 Singles chart has listed 25 positions.