Swim Trunks Market Report: Sales Volume, Market Share, Leading Brands & Market Trends

FT FENTENG is the best-performing swim trunks brand in July 2026, moving 5,000 units across 2 ASINs for 26.3% of Top 10 volume. maamgic follows with 5,000 units (26.3%), ahead of ELETOP on 4,000 units (21.1%).

With 6 brands splitting the Top 10 and 73.7% of volume sitting with three of them, this is a concentrated shelf — the leaders hold multiple listings or one very high-velocity ASIN, so a new entrant competes against established review moats rather than an open field. Average selling prices among the leaders run from $17.99 to $22.99, 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, one ASIN forced its way in: B09QD21VKB booked 1K units at $23.99, with ▲ 0.0% MoM change. On the growth side, B0GL1JJTSP leads positive momentum with ▲ 700.0% MoM growth on 800 units, with B0953GTYBR close behind at ▲ 166.7% MoM on 800 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already changed hands — an incumbent gave up its place to make room, so any competitive set drawn up a month ago is now out of date.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.