The financial tools of investors.
For collectors.
Cault connects official sources to give you, in real time 1, what no spreadsheet can: a living financial portfolio for all your collections.
Market prices
Real market prices — automatically.
Forget manual searches on BrickLink. Cault queries official sources directly and updates your prices in the background. Open the app, everything is up to date.
- Real-time¹ market prices — LEGO, Pokémon TCG, Magic…
- Official retail price from dedicated sources per universe
- 30-day cache — automatic update every 30 days
- On-demand refresh on any item
Example — Set 75192 Millennium Falcon
Purchase price
What you paid
Retail Brickset
Current LEGO.com price
Marché BrickLink
Sealed market price
Potential ROI
vs your purchase
Portfolio — Global view
Total value
4 820 €
Invested
2 980 €
Unrealized gain
+1 840 €
Overall ROI
+61 %
Black Lotus Alpha
Charizard Holo Base Set
UCS Millennium Falcon
Technic Bugatti Chiron
Automatic ROI
Your ROI calculated in real time 1, for every item.
Every item in your collection is compared to its current market price. Cault calculates your unrealized gain, your per-item ROI and your overall portfolio performance — with no manual entry.
- Per-item ROI (purchase price vs current market)
- Global portfolio ROI across all collections
- Automatic ranking of your best investments
- Unrealized gain vs realized gain
- Price history charts
Finances tab available on the Pro plan. Free and Essential show market position per item, without computed ROI.
Advanced analytics
Your collection analysed like a financial portfolio.
Beyond per-item ROI, Cault calculates the metrics real investors use. Diversification, volatility, Sharpe ratio — available for all your collections.
Portfolio health score
Excellent1.42
Sharpe
8.3 %
Volatility
−3.1 %
Break-even
Benchmark
Performance ranking
Your items sorted by ROI, absolute gain or period performance. Instantly identify your best and worst investments.
Wealth curve
Visualise the evolution of your total portfolio value over time. Week, month, year — the chart adapts to your horizon.
Performance heatmap
Calendar view of price movements month by month. Spot seasonal patterns — some items systematically rise at year end.
Portfolio health score
A composite score based on diversification, item liquidity and overall performance. Know in one number whether your collection is well balanced.
Advanced indicators
Sharpe ratio, volatility, break-even — the same metrics as a financial portfolio, applied to your collection. For collectors who think like investors.
PDF report export
Generate a complete portfolio report in one click — total value, per-item ROI, history. For your records or your accountant.
Portfolio benchmark
Compare your collection's performance against the Livret A, French inflation and gold. Know whether your passion is as profitable as a classic financial investment.
Advanced analytics available on the Pro plan.
Price alerts
Never miss the right moment to buy or sell.
Set a target price on any item — your collection or your wishlist. Cault monitors constantly and notifies you as soon as the threshold is reached.
- "Sell" alert: notified when the price exceeds your threshold
- Sell target: alert with direct CTA to sell when your target price is reached
- "Buy" alert: notified when the price drops below your target
- Wishlist alerts — anticipate retirements
- Daily summary or immediate notification
Concrete example
You set a sell target at €1,800. As soon as BrickLink reaches that price, Cault notifies you with a "Sell now" button — one click and you're in the sell form.
🎯 Target reached
UCS Millennium Falcon
Market price: €1,502 — your sell target is reached
⏳ Monitoring
Charizard Holo Base Set
Buy target: €250 · Current price: €285
📉 Opportunity
Black Lotus Alpha
Price down 8% this month — wishlist
Price alerts available on the Pro plan.
Inventory & Catalogue
Every item in your collection, precisely tracked.
Thousands of items in the database — LEGO, Pokémon TCG, Magic — you search, you add, Cault does the rest.
Catalogue search
Find any item by number or name — LEGO, Pokémon TCG, Magic. Official databases integrated.
Detailed conditions
Sealed / New without box / Used. Each condition automatically adjusts the market value estimate.
Official images
Official photos from BrickLink and JustTCG. No generic images: the real image of each item.
Transaction history
Every purchase, sale or trade is logged. View the complete history of any item or your portfolio.
Smart wishlists
Add items to watch. Cault alerts you when prices move — ideal to anticipate retirements or buy at the right time.
Duplicate merging
Own multiple copies of the same set? Enable the merged view to group them on one line. When selling, choose which one — sealed, built or disassembled.
Multiple collections
Create a collection per theme, universe or storage location. The Collections page shows each one's stats (value, ROI, item count), one-click renaming, and you can move an item from one collection to another from its detail page.
Per-collection privacy
Each collection is private, public, or visible to friends only — you decide who sees what, instead of an all-or-nothing setting for your whole account.
Fiscal CSV export
Generate a summary of your disposals by fiscal year: purchase date, purchase price, sale date, net gain. Ready to send to your accountant.
Collection import
Import your existing collection in one click — CSV, XLSX, JSON or XML file (Rebrickable, Brickset, BrickEconomy, BrickLink or Cault template). Automatic format detection, editable preview, search for unrecognised sets, and price/image enrichment.
Insurance report
Export the list of all your items with their current market value and the total value of your collection. Document ready to present to your insurer.
Items marked Pro require the Pro plan.
Community
See how your collection compares — without ever exposing it.
Every item in your collection shows its place among Cault collectors: rarity, average price paid, popularity. Free, on by default, with no individual data ever made public.
- Set rarity & average price paid — shown on every item, free, no opt-in
- See which of your friends already own a given set
- Optional ranking: your position by value, ROI and theme among other Cault collectors (off by default)
- "Sets in common" — the most shared, rarest, most expensive and most wishlisted sets in the community
- List a set you'd like to part with: automatic Cault price by condition, visibility from private to a public link — contact always happens outside Cault
- Aggregated data only — a strict anonymisation threshold applies everywhere
Not a marketplace
Community informs you and lets you signal what you'd like to part with — never automated matchmaking, messaging, payment or commission. Contact stays between collectors, outside Cault.
Example — Set 75192 Millennium Falcon
Set rarity
Rare set12 / 249 collectors own this set
Average price paid
742 €
In wishlists
37
3 friends own this set
Brickset Dates
Never be caught off guard by a retirement.
Brickset provides official launch and retirement dates for every LEGO set. Cault integrates them directly into your collection. You know which sets are disappearing — before everyone else.
- Official launch date (LEGO.com)
- Estimated retirement date by Brickset
- Automatic "Retiring soon" indicator
- Retail price history since launch
- "Upcoming retirements" page — all sets retiring in the next 6 months, with buying signals
Why this matters
LEGO sets generally rise in value after retirement. Knowing a set is retiring in 3 months gives you an edge to buy at the right time.
10326 Age of Natural History
Retiring soonRetiring: Dec. 2026
Retail
249,99 €
Market
310 €
75341 Luke Skywalker's Podracer
AvailableLaunched Oct. 2022
Retail
229,99 €
Market
280 €
71043 Hogwarts Castle
RetiredRetired Sept. 2023
Retail
—
Market
650 €
Your collection has value. Time to know it.
Free. 2-minute setup. Your first ROI displayed immediately.