CoinDuel
Fantasy Crypto Trading
Real-time market data. Zero real money.
Compete. Prove it. Duel.
Every screen, designed.
Fantasy crypto trading
Zero risk, all skill
Real market data
Zero risk, all skill
Live prices & charts
Real-time scoring
Trade & manage
Rank by format
Up to 50 players
DMs & group messages
Format, mode & rules
Chats & notifications
Active & past games
Account & subscription
Figma · React Native · Expo · Supabase · Claude Code · GitHub · Vercel · GA4 + Clarity · Google AdMob · Google Cloud
Product strategy, UX/UI design, design system, full-stack mobile application
Everyone has a market opinion. Nobody can prove theirs.
Crypto apps are solo. Real trading risks real money. There's no arena to compete, no scoreboard to settle the debate. Everyone has a take — nobody has receipts.
Build your portfolio. Compete. Prove it.
CoinDuel turns market opinions into a competition. Build a portfolio of real coins, compete against friends or strangers using live market data, and let the market decide who was right. The name says everything — a duel. Two people, two portfolios, one winner. Coin. Duel. That's the whole product.
Fantasy sports proved competition makes everything more engaging. The same behavior exists in crypto. Crypto apps are built for solo trading. Fantasy apps are built for sports. The intersection — social, competitive, market-driven — doesn't exist yet.
That's the gap CoinDuel fills.
to be captured.
falls short.
| DraftKings | Coinbase | CoinDuel | |
|---|---|---|---|
| Real market data | — | ✓ | ✓ |
| Zero financial risk | ✓ | — | ✓ |
| Head-to-head competition | ✓ | — | ✓ |
| League play | ✓ | — | ✓ |
| Social layer / group chat | ✓ | — | ✓ |
| ELO ranking | — | — | ✓ |
| Crypto focused | — | ✓ | ✓ |
| Year-round gameplay | — | ✓ | ✓ |
One gap.
gameplay.
Game Formats
1v1 against a random opponent or an invited friend. League play in standard public or private contests. Fake money, real market data, one winner.
How You Play
Create a game, build your portfolio with real coins, and trade freely for the duration of the contest. Buy and sell as many times as you want within your allocated budget.
Trading Mechanics
Simple, intuitive, familiar. No game mechanics that don't exist in real trading. The goal is to feel as close to real trading as possible — without the financial risk.
ELO Ranking
Every match adjusts your ELO. Seven tiers from Bronze to Legend. Beat higher-ranked players, climb faster. Drives matchmaking and powers the global leaderboard.
Roadmap
Additional trading mechanics planned post-launch to add deeper strategy without adding complexity. The foundation is intentionally simple — depth comes later.
Markets
Total market cap hero chart with timeframe toggles. Top 100 coins sorted by gainers, losers, or market cap. Search, filter, and bookmark — all above the fold. The home screen is a data dashboard, not a menu.
Live contest
Auto-zoom score chart tracks you against your opponent in real time. Wallet balance, score, coin positions, and swap action — all on one screen. The countdown timer creates urgency without noise.
Position detail
Average cost, current value, percent change, and point value — the math is done for you. Trade directly from the same screen. No navigation required to take action on a position.
Leaderboard
Rankings filtered by format, mode, and season. Top 3 players highlighted with avatar cards. Your rank pinned at the bottom so you always see where you stand relative to the best.
League play
Up to 50 players in a single contest. Score comparison chart, live standings table, and your full portfolio. Player tabs let you switch between your view and your competitors'.
Reusable.
Components
Coin list items with sparkline charts, contest cards with live countdowns, rank cards with tier badges, position detail rows, wallet/score stat blocks, standings tables, format pills (1V1, LGE, PVT).
Patterns
Dropdown filters, search bars, dual-action button pairs reused across contexts. Contextual action button in the top right of every screen. Back navigation always returns to the tab root.
Visual Language
Black, white, green. Gray containers. Minimal palette, consistent type hierarchy. No gradients, no shadows, no 3D. Flat, calm, data-forward.
Market
Top 100 coins. Real-time prices, charts, sorting. Bookmarks top right.
Leaderboard
Rankings by format — daily, weekly, season. Friends list top right.
Contests
Central hub. Create, track, review. Enlarged active state. Rules top right.
Inbox
DMs and league group chats. Notifications top right.
Account
Profile, settings, subscription. Settings top right.
assumptions before testing.
More access.
Core gameplay, ad-supported
Access to top 100 coins. Live market data. Ad placements between contests — never mid-gameplay.
More access. No limits.
Expanded coin access. Unlimited simultaneous games. Ad-free experience. Details finalized post-beta.
Zero noise.
Black, white, and green. No gradients, no shadows, no 3D. The visual language is intentionally restrained so data and gameplay take center stage. Syne for headlines — bold, geometric, competitive. Space Mono for everything else — technical, precise, data-ready.
Two platforms.
React Native + Expo
Single codebase for iOS and Android. Expo Router for file-based navigation. Zustand for state management with persist middleware.
Supabase
Handles authentication, player profiles, ELO ratings, contest data, and real-time score tracking. Row-level security for data isolation.
CoinGecko API
Real-time coin pricing, market data, and chart data. Cached locally with rate-limit handling for performance.
Google AdMob
Banner and rewarded ad placements. Ad revenue as the primary free-tier monetization model.
Stripe
Premium subscription management. Handles upgrade flows and billing for the paid tier.
Google Cloud
Backend services, edge functions, and scheduled jobs for price updates and tier calculations.
it shipped.
Early Concept Testing
Showed wireframe flows to 10 potential users — a mix of crypto traders and fantasy sports players. The fantasy crypto concept landed immediately. Zero confusion on the core idea.
Adding Coin News
User research revealed players wanted to make informed trading decisions without leaving the app. Added aggregated coin news with an in-app browser so users can research before making a move.
Removing the Draft
The draft mechanic never made it to UI. During early concept conversations with potential users, explaining the draft flow consistently caused confusion. When the same explanation fails repeatedly, that's the signal — the concept itself is the problem, not the explanation. The decision was made before a single screen was designed. Free portfolio trading replaced it entirely.
Removing the Boost Mechanic
Early versions included a boost multiplier to amplify gains. Testing showed it wasn't intuitive and didn't map to any real trading mental model. It was cut entirely. Spot trading is universally understood — the simpler mental model won.
What Worked
ELO ranking motivated competitive players to keep playing — tier progression became a game within the game. Friend-group framing was the strongest acquisition hook in testing.
Closed Beta
12 users. Bug validation and stability testing before expanding the pool.
with real users
Product Strategy
Define the problem, market positioning, game mechanics, scoring formula, and monetization before touching any tools.
Design System
Build the component library, design tokens, and screen patterns in Figma. Every decision documented with rationale.
AI-Assisted Build
Claude Code receives well-defined specs with correct semantics. MCP connects Figma directly to production. No drift between design and code.
Ship
Test, iterate, deploy. The design thinking done upfront is why a solo build ships in weeks, not months.
Try CoinDuel
Fantasy crypto trading powered by real-time market data. Compete. Prove it. Duel.
