it depends on what the wavy part looks like. if its a round bubble or a finger shapped bubble the its from the tire being pinched against the rim.

if its an indentation then its the seam of the tire. that type of seam is mostly seen on truck and suv tires, but i have seen it on performance and regular tires as well. the indentation is not anything to worry about. it is common.

some may disagree with me and thats fine, its not like i managed a tire shop for years, or have been sent to many classes about tires and construction of tires by major companies such as Goodyear, Michelin, and Continental.

if you said you had goodyear trackers (the original version) i would say take them back right away, because they have a design flaw and is why they are no longer being produced.