Last weekend, the New York Times ran a feature on why trousers—or pants as they’re known in the US—have become so large again.

Indeed, look around and you might believe that baggy fits have put the final nail into the coffin of skinny jeans. But retailers and consumers shouldn’t get too comfortable in their big pants.

Wide-legged bottoms—including the straight, flared, bootcut, barrel, balloon and carrot variations—are rapidly taking market share from tight-fitting ones. Yet with the rise of super-fast TikTok trends, often fused with a sense of nostalgia, interest in slim-fit silhouettes is rising. Before you cry out in horror, no, this isn’t a return to the tyranny of skinny jeans. But it is a reminder that a myriad of often competing styles can exist all at once in the fashion universe.

While the proliferation of trends is currently boosting denim sales, it also means that store chains must monitor them all and have a selection embracing all manner of leg proportions—a challenge as fraught as choosing the right pair of jeans.

Skinny ruled for more than a decade, starting from around 2005. The first rumblings of change came around 2016, when fashion brand Vetements, (co-founded by Balenciaga designer Demna Gvasalia) unveiled a slightly wider-legged, uneven-hemmed garment refashioned from vintage jeans, which sparked a raft of high-street imitations.

But the move into the mainstream came in the wake of the pandemic. After spending time in sweatpants, we were reluctant to squeeze back into tight-fitting trousers, particularly as many of our waistlines had expanded. Since then, circumferences have stretched ever further, thanks to LVMH’s influential Loewe brand and most recently Richemont’s Alaia.

Consequently, the number of wide-legged jeans on retailers’ websites in the US and UK is surging—led by the barrel, with its fitted hips, curved legs and tapered ankle—while skinnies are contracting, according to retail intelligence company EDITED.

Jeans giant Levi Strauss & Co. said recently that looser fits now represented half of its women’s business. At Marks & Spencer Group Plc, which accounts for one in five pairs of women’s jeans sold in the UK, sales of wide-legged styles have doubled over the past year, outpacing expectations. The company will soon unveil its widest-ever jean, the drapey palazzo.

But interest in a slimmer silhouette has risen over recent months. Thanks to Instagram and TikTok, there has been a democratization of fashion commentary. The “Internet of Trends,” as forecaster WGSN dubs it, tears through different looks at an alarming speed, making styles ever more extreme. 

We have cycled through Y2K, characterized by low-rise cargo pants and crop tops, to early noughties’ micro-miniskirts and Uggs. Some social media users have speculated that interest in skinny jeans has coincided with the popularity of the boot (it’s hard to tuck bellbottoms into the fur-lined footwear). The film Saltburn thrust mid-noughties fashion— i.e., peak skinny jean—into the limelight, while some TikTok creators have been yearning for the 2010s, with the resurgence of ballet flats and skull prints.

Prada SpA’s MiuMiu, the world’s second-hottest brand at the moment, according to fashion platform Lyst, recently sent skinny jeans down the runway in Paris, while street-style influencers have begun to dabble with more figure-hugging forms.

And let’s not forget, for some people (ahem, millennials), the slimmer fit never went out of style. Skinnies still account for around one-third of M&S’s women’s jeans business. That is much less than a few years ago, but it’s still significant, dominated by the best-selling Ivy skinny, priced from £25 ($32) to £32.50.

Among customers not wedded to any particular fit, skinny has yet to make a comeback. The style accounts for a lower proportion of jeans currently selling out on retailers’ websites in the US and UK, and they are more heavily discounted, according to EDITED.

If a small-versus-slouch standoff emerges, it will have significant consequences for store chains and manufacturers.

The good news is that trends, especially lots of wearable ones, stimulate sales. A wide array of denim shapes, shades and washes means there is likely to be something for everyone. Diversity of styles also encourages women and men to buy more than one pair—perhaps why once humble workwear is on such a tear. And the popularity is not confined to jeans. It’s spilling over into jackets (think double denim) and skirts. Add in the fact that each type of jean needs to be dressed with a different top and shoe, and this should be great for retail revenues.

But companies will have to monitor silhouettes carefully. They must keep a close eye on the catwalks, but also on street-style influencers and social-media creators, to figure out just what width of leg their customers demand. And they need to maintain flexibility in their supply chains, so that they can adapt production at the first sign of a shift.

Any miscalculation in the baggy-to-bum-hugging ratio risks leaving them with unwanted stock, which will have to be marked down and will eat into profits. Ultimately, how we choose to dress our legs matters to the bottom line.

Andrea Felsted is a Bloomberg Opinion columnist covering consumer goods and the retail industry. Previously, she was a reporter for the Financial Times.