Luxury resale is taking over. From secondhand Birkins to used Rolexes, here's what you need to know.

Resale has taken over luxury shopping — and it's showing no signs of slowing down.

The secondhand fashion market is growing as much as three times as fast as the firsthand market, and 59% of shoppers said they are likely to shop resale in 2026, according to a November report published by The Business of Fashion and McKinsey.

By 2030, the global resale market is expected to reach as much as $360 billion, according to an October report from Boston Consulting Group.

For luxury secondhand retailers like Fashionphile and The RealReal, that has meant major growth. Both posted double-digit percentage gains in 2025.

There are a few reasons for the secondhand surge.

Prices have climbed in the luxury sector since the pandemic, when brands capitalized on increased spending power. Inflation and tariffs have pushed prices even higher. Secondhand offers a more affordable option.

Plus, the proliferation of resale platforms has increased accessibility — online marketplaces accounted for 88% of resale spending in 2024, according to the McKinsey report — and the implementation of stricter guardrails around authenticity has made shoppers more confident.

"It's becoming something that's much more sustainable and part of the way people engage in the category," Pierre Dupreelle, a managing director at Boston Consulting Group, told Business Insider of luxury shoppers.

For every secondhand buyer, there is a seller — and people are cashing in on the trend.

People now shop with ROI in mind. In a 2025 survey, online thrift store ThredUp found that 47% of consumers consider the resale value of clothing before making a purchase; among those aged 18 to 44, that number ballooned to 64%.

"You own a piece of capital that you can apply to something else; it's money in your closet, sitting and waiting to be spent," Lara Osborn, the SVP of merchandising and fulfillment at Fashionphile, told Business Insider.

But sellers, beware: Like with stocks, investing in luxury is not a sure thing. So if you are going to shell out for a Hermès Birkin or Rolex, make sure you actually like it.

A good rule of thumb is to consider it a shopping victory "when you can buy, use, and enjoy it, and sell it at some point and get a big portion of your money back," Osborn said.

Business Insider has spoken with experts at luxury resale platforms like Fashionphile, The RealReal, and Bob's Watches about which items hold their value the best, and what can be resold for more than its list price.

Read on for their tips and tricks before you become a fashion flipper.