Altermagnets are an emerging class of collinear magnets featuring two qualities previously believed to be incompatible: a vanishingly small net magnetization and spin-polarized electronic band structures. These features are well-understood from the unusual symmetry properties of altermagnets, which can be related to an underlying magnetic multipolar ordering in the systems. In this talk, I will describe how such multipolar character governs transport phenomena such as the anomalous Hall effect and spin transports, shedding light on the origin of the unique characters of altermagnets.