When Serena Williams stepped onto the red carpet at the 2019 Met Gala, it wasn’t her tennis-ball yellow Atelier Versace gown that got people talking. Rather, the most buzz-worthy part of her outfit was the pair of matching Off-White x Nike sneakers peeping out from her dress’ cascading train. In this iconic moment, the message was clear: Sneakers are now officially part of the dress code at every occasion imaginable, including those sanctioned by Anna Wintour.

Of course, this is a movement that’s been building since the term “fitness fashion” was coined in the mid-2010s. But since the beginning of this year, anytime-anywhere sneakers seem to have hit a tipping point—a year ago, they may have been considered a trend, whereas now they’re a legitimate wardrobe staple. Walk down any city street in the world right now, and you’ll likely see tons of women wearing sneakers with dresses and midi skirts. (Not just for casual Sunday brunches, but for weddings, work, and first dates, too.) The same will surely be true this fall, if the sneaker-filled autumn/winter 2019 runways are any indication. Expect to see lots of hiking-inspired styles hit when the weather turns cool—we called the rise of “gorpcore” sneakers as part of our 2019 Wellness Trends preview last December, and the global fashion weeks in February proved the prescience of that prediction.

“Cute factor plus comfort factor equals a cool way to finish just about any look.” —Kirta Carroll, Foot Locker

NPD Group data confirms we’re in the midst of a sneaker surge. While sales of performance kicks—aka those specifically designed for sports like running and basketball—declined in 2018, fashion-driven styles like the Fila Disruptor helped nudge the overall athletic footwear market to single-digit growth from the previous year. And although sneaker sales slowed a bit in the first quarter of 2019, we’ve still seen lots of high-profile brands jump into the arena with new trainer collections of their own, including Everlane and Madewell. Lululemon is also developing a footwear line, in yet another nod to sneakers’ long-term staying power.

It’s not surprising that the athleisure explosion of 2016—when we all started trading our jeans for leggings and our business-casual garb for “workleisure”—has since trickled into footwear. “Sneakers have become the foundation of the modern uniform, largely driven by the casualization of the wardrobe,” says Alison Melville, Everlane’s general manager of footwear and accessories.  “They’re the focal point of the wardrobe, whether you’re pairing them with denim or a designer dress.”

Indeed, comfort is king in fashion right now—and who can blame us for not wanting to contort our feet into wobbly heels when things like burnout and climate change are shaking our foundations so vigorously? But Kirta Carroll of Foot Locker doesn’t believe that’s the only thing driving Sneakermania 2019. “While nobody can deny sneakers are a much more comfortable alternative to heels, I think we can all agree sneakers have never looked better,” says Carroll, the brand’s vice president of North American consumer concepts for women and kids. “We’ve certainly never had the breadth of options and brands we have today. Cute factor plus comfort factor equals a cool way to finish just about any look.”

And unlike many other cult fashion items, like luxury bags and designer jeans, sneakers are far more affordable and widely available—and, thus, democratic. “The widespread introduction of sneakers in a women’s everyday life has, in a way, broken down the barriers to high fashion,” says Vanessa Beckett, vice president and general merchandise manager at Bandier. “With sneakers, women can feel comfortable and fashion-forward at the same time, at a moderate price point. I believe women feel empowered having the option of wearing sneakers for any occasion.” For instance, a pair of regular Nike sneakers that look similar to Williams’ Met Gala pair cost around $100. Any of the other shoes at that event, however, would likely be priced around four to five times that amount—and they’d have a much smaller audience scrambling to get their hands on a pair.

So what’s next for sneakers?

From a style perspective, Beckett reports that all-white sneakers are performing particularly well at Bandier right now, and that probably won’t change any time soon. “[Our customer] likes something fresh that can be worn from gym to everyday and vice versa,” she says, adding that chunky platforms are also “in full effect.” Heading into fall, she predicts that women will start wearing high-tech performance sneakers with dresses and other outside-the-gym items, while Carroll says to keep an eye out for “rich and bright colors,” including neons and autumnal hues, as well as animal-print accents. (I suspect we’ve got the leopard-skirt trend to thank for that one.)

But perhaps the biggest developing story in the sneaker world is the one around sustainability. “Sneakers have become the ultimate fashion statement, meant to be collected and refreshed with each new style or drop. This is a disaster for the environment,” says Melville. “Many people don’t realize sneakers are made almost entirely of plastic.” This is why Everlane’s unisex sneaker brand, Tread by Everlane, was designed to be as eco-friendly as possible. “We focused on creating a sneaker sole [that’s] 94.2 percent free of virgin plastic, working with a tannery that uses less energy and water, and completely offsetting the carbon emissions that remain,” Melville explains.

Everlane’s not the only sneaker brand prioritizing the earth. Last month, Native dropped the first plant-based, 100-percent biodegradable shoe collection, made from materials like pineapple fibers, linen, and eucalyptus. Nothing New debuted in June with a direct-to-consumer line of low-tops made from recycled fishing nets and plastic bottles. And established brands such as APL and Veja have unveiled sneakers made from Merino wool and corn, respectively. They’ve got a ready audience—40 percent of consumers, particularly those from 18-34 years old, say sustainable materials are important to them when they’re making a footwear purchase.

The most sustainable choice of all, however, is not buying brand-new trainers in the first place. Luckily, the sneaker resale market is undergoing a massive expansion of its own—it’s currently worth $2 billion in the U.S. and is projected to grow to $6 billion by 2025—which means covetable secondhand kicks will soon be a lot easier to come by. Since December, sneaker resale startup StockX raised $110 million in a Series C funding round and achieved “unicorn” status with a $1 billion valuation; Foot Locker invested $100 million in sneaker resale platform Goat Group; and Farfetch acquired sneaker reselling store Stadium Goods for $250 million. While these businesses cater primarily to the streetwear crowd, luxury fashion is also getting in on the resale rush. Consignment marketplace The RealReal reports that demand for Yeezy sneakers has increased by nearly 600 percent year over year, while kicks by Nike, Balenciaga, Gucci, and Louis Vuitton are also on the rise. (For non-designer styles, check out platforms like Poshmark and ThredUp.)

Bottom line: Although they’ll continue to evolve in terms of style and sourcing, sneakers aren’t giving up their position of fashion-scene HBIC any time soon, if ever. As someone who’s saved a significant amount of money on blister patches this year—and is now rarely taller than my dates—I’ll click my heels to that.

To help your favorite sneakers last as long as possible, check out this dish-soap hack that’ll make them look brand-new—and this baking-soda trick for the days you wear them without socks.