What is worth collecting? A guide for investors and collectors (2026)

Collecting is more than just a hobby; it is a way to express yourself, discover history, and build long-term wealth. Today, more and more people are combining their passion with...

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  • Author of the entry: Mennica Skarbowa
  • Date of entry:

Collecting is more than just a hobby; it is a way to express yourself, discover history, and build long-term wealth. Today, more and more people are combining their passion with investing: collections should be pleasing to the eye and generate capital. How to choose areas where the chances of maintaining or increasing value are greatest?

TL;DR (in a nutshell)

  • The most solid foundations are found in categories with documented rarity, confirmed authenticity, and strong secondary demand: collectible coins and banknotes, select watches, wine/whiskey, classic cars, and art. Ten-year data (Q4 2014–Q4 2024) shows, among other things: whiskey +192%, designer furniture +141%, watches +125%, cars +59%, coins +48%, art +54% (KFLII index – Knight Frank).
  • LEGO: Long-term research (1987–2015) indicates an average return of approximately 11% per year on the secondary market, but there is significant variation between sets. Limited editions in their original boxes perform best.
  • NFTs and digital collections: the market is highly volatile. The boom of 2021 was followed by a crash; in 2025, there are periodic rebounds in volumes, but values are still lower than at the peak of the bull market. Treat them as speculation, not the foundation of your collection.

Table of contents

What really increases in value?

In 2025, Knight Frank summarized the 10-year results (up to Q4 2024) for the main collectible categories. The strongest categories of the decade were: whisky (+191.7%), designer furniture (+140.9%), watches (+125.1%), followed by classic cars (+58.9%), art (+54.0%), and coins (+47.5%). At the same time, 2024 was a difficult year for art (-18.3%) and wine (-9.1%). The moral of the story: look at the decade ahead and diversify.

Numismatics and banknotes: classics with a strong foundation

Commemorative coins and collector banknotes have an advantage: controlled circulation, specific specifications, and a regulated market for issuance (e.g., NBP issues, Kolekcjoner store). In the long term, Knight Frank's "coins" category has grown by ~48% in 10 years. Key value factors: rarity, condition, origin (provenance), and confirmed authenticity.

Good purchasing practices

  • Buy from reputable entities and consider certification/grading (NGC, PCGS). Encapsulation in airtight holders increases market confidence and facilitates resale.
  • Attach/archive documents: certificate, invoice, NBP emission catalog, photos.

Art and antiques: high potential, but require knowledge

Art can grow, but it is cyclical 2024 saw a decline in art indices and a drop in sales on the global market (UBS/Art Basel report). That is why the following factors are particularly important in art and antiques: expertise, provenance, condition, fashion, and segment liquidity.

Collectible toys and LEGO sets

Pop culture figurines (Star Wars, Marvel, Disney) and LEGO sets have active secondary markets. In the HSE study, LEGO achieved an average of ~11% per year (1987–2015). Limited editions, in intact boxes, complete, with documentation, hold their value best, but selection is key; not every set increases in price.

NFTs and digital collections: high volatility

After the euphoria of 2021–2022, the market corrected sharply; in 2025, we are seeing a rebound in activity (e.g., Q3 2025 volume growth), but this is still a segment with elevated risk and uncertain demand sustainability. Consider it more as a speculative addition than the core of your collection.

What really builds the value of a collection?

  • Rarity and circulation (limited editions),
  • Condition (gradation, original packaging),
  • Authenticity and documents (COA, grading, provenance),
  • Secondary demand and recognition (active market, iconic design),
  • Ease of verification (series, certificate, issue catalog).

How to safely store and preserve collections?

Stable conditions are paramount. For mixed collections (paper + metals), aim for 18–22°C and approx. 35–55% RH (relative humidity), with limited fluctuations.

  • Metals/coins: the lower the humidity, the safer it is for corrosion; museums recommend approx. ≤45–50% RH (even lower for iron). Avoid PVC, use moisture absorbers, caps/holders.
  • Paper/stamps/banknotes: dark, cool, dry, stable ~30–50% RH; albums/folders made of acid-free materials, no UV light. Reputable philatelic sources usually indicate around 50–55% RH as safe for stamp gum.

Pro tip: Stability is more important than the "ideal number." Large fluctuations in temperature and humidity accelerate degradation.

Storage checklist

  • Acid-free boxes/albums, capsules, and caps; cotton gloves for metals; stamp picks.
  • Dehumidifiers/silica gel, hygrometer; no sunlight.
  • Do not clean with aggressive agents (especially coins!). Cleaning can immediately destroy the collector's value.
  • Regular inspection and documentation (photos, numbers, invoices).

The most common risks and how to avoid them

  • Counterfeits → buy from reputable sellers, use grading, and verify certificate numbers.
  • Storage damage (corrosion, mold, paper toning) → RH/temperature control, acid-free materials.
  • Low liquidity of niches → prefer series/brands with an active secondary market; diversify.
  • Excessive optimism about returns → base decisions on data, not anecdotes (e.g., KFLII indices).

How to get started: the easy way

  • Select 1–2 areas (e.g., NBP coins and foreign gold/bullion issues).
  • Define criteria: print run limit, condition (UNC/Proof), certificate/grading.
  • Take care of storage (capsules, albums, RH control).
  • Keep records and regularly review the secondary market.

This information is of a general nature only and should not be treated as investment advice within the meaning of applicable law. Investing in precious metals, among other things, may involve risk. Before making any investment decisions, it is recommended that you consult a financial advisor for an individual assessment of your investment options.

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