Underwire Tankini Market Report: Sales Volume, Market Share, Leading Brands & Market Trends

B2prity is the best-performing underwire tankini brand in July 2026, moving 1,000 units across 1 ASIN for 15.6% of Top 10 volume. ROSEWE follows with 1,000 units (15.6%), ahead of MODLILY on 800 units (12.5%).

Volume is spread across 10 brands, with the top three holding 43.8% between them. No single label controls the shelf, which usually leaves room for a well-differentiated listing to take share without outspending an incumbent. Average selling prices among the leaders run from $37.99 to $39.99, which frames the price band a competing listing has to justify.

Based on July 2026 data, this shortlist surfaces the two kinds of ASIN worth keeping an eye on — the ones that just broke into the Top 10, and the ones growing fastest month over month. Specifically, 2 ASINs forced its way in: B0F7XD2K7G booked 500 units at $36.99. On the growth side, B0FDGPY8XB leads positive momentum with ▲ 100.0% MoM growth on 100 units.

The two signals carry different weight. A fresh entrant means share has already changed hands — an incumbent gave up its place to make room, so any competitive set drawn up a month ago is now out of date. A steep growth rate works as the earlier warning: it marks demand that is still compounding, usually a month or two before the ranking catches up to it.