The collectibles market is booming with tennis tournaments in Spain: if you have an item from your idol, you could have a treasure.

The month of April has come to an end, and with it, the two most important tennis events on the Spanish tennis calendar: the Conde de Godó Trophy (ATP 500) in Barcelona and the Mutua Madrid Open (Masters 1000). Thousands of Spanish fans have enjoyed a month of tennis from their favorite stars, and many of them have obtained a photo, signature, towel, or wristband of their idol, a treasure that, beyond sentimental value, can fetch thousands of euros on the sports collectibles market.

The rise of so-called sports memorabilia is growing worldwide, and also in Spain, where the number of items up for auction increases with each major event. This is what Ana María Covrig , a sports memorabilia expert at the collectibles website Catawiki, told 20 Minutos .

"Typically, we see a slight increase in the number of lots available for auction during major tournaments," says the expert, who also notes that, in the case of tennis, "the number of lots doubled in 2024 compared to 2023."

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It seems logical that our country is a "leader in tennis memorabilia sellers," a phenomenon that the auction platform links to the existence of "legendary players like Rafael Nadal." Ana María Covrig is clear, therefore, that "it's no surprise that Spain is bringing unique and significant pieces of tennis history to an increasingly global audience."

Now, given the existence of a niche market for collectibles, what is the process an object follows from the moment it leaves the hands of a tennis star until it is auctioned for a substantial sum? The specialist contacted by this medium also answers this question.

What to do if you want to sell an item

Let's say, for example, that current star Carlos Alcaraz signs and gifts you one of his wristbands after a match. From there, countless factors can affect its value, starting with the very nature of the object itself. "Balls are often valued differently than jerseys, wristbands, or other memorabilia," says Ana María Covrig, before detailing that "several factors influence these fluctuations, such as the time of year, ongoing tournaments, and the athlete's current performance ."

Of course, above all, and logically, authenticity is the main value, so a "certificate of authenticity can significantly increase the value of an item," Covrig recalls.

If you, the owner of that hypothetical wristband worn and signed by Carlos Alcaraz after a match at the Mutua Madrid Open , want to know its monetary value and start an auction , you must follow a series of strict steps detailed here by the Catawiki portal.

First, "experts assess the item's credibility through a multi-step process" that checks for "irregularities or signs of inauthenticity." Second, the seller is subjected to a comprehensive questionnaire in which they are "requested concrete evidence" such as "photos or videos of the signing," "certificates of authenticity," or even a "tournament ticket to confirm their presence at the event" where they supposedly obtained the item.

Once the process is complete, the platform's experts use all the information to make a "fair and accurate value estimate" before the item is listed and the auction begins.

The most valuable tennis objects

The process is long and exhaustive, essential to ensure that "both the seller and the buyer, often a passionate collector, can feel secure and satisfied" when exchanging an item capable of fetching a high value. In the case of tennis, the platform reveals to 20 Minutos the items auctioned for the highest price: Novak Djokovic's special sneakers commemorating his 311 weeks at No. 1 (€3,101), a bandana worn by Roger Federer in his final season (€1,750), a racket used and signed by Rafa Nadal (€1,402), and a set of balls signed by some of the world's best players (€800).

Collecting fever has always been an important part of the sports business, although Catawiki states that "sports memorabilia is increasingly seen as an alternative investment," which is growing in the specific case of tennis.

If you have that wristband signed by Alcaraz at the Mutua Madrid Open, you have a treasure at home. However, the emotional value of a piece can far outweigh its economic value. Passion, the driving force of sport, still prevails in a world where there have already been problems with this type of auction market. An example of this is the complaint made publicly by Barça players just a few months ago, in which they pointed out the increase in fans crowding outside the Sports City to request autographs that were then sold online.