1. A system, comprising: a non-transitory computer readable medium, comprising instructions which, when implemented by a processor, cause the processor to perform operations comprising: generate a new category different than an established category, wherein a first subset of content items are associated with the established category according to an origin of the content items of the first subset, wherein a second subset of the content items are associated with the new category according to an origin of the content items of the second subset, wherein the origin of the content items of the first subset is different than the origin of the content items of the second subset; for reach of the first and second subsets of content items: apply a first weight to a rate of change at which content items are added to the respective first and second subsets over time to obtain a weighted rate; apply a second weight to a number of content items included in the respective first and second subsets to obtain a weighted number; and combine the rate as weighted and the number of content items as weighted to obtain a weighted value; identify a trending topic corresponding to one of the new category and the established category based on the respective weighted values relative to a threshold; and cause information related to the trending topic to be displayed on a user interface.