How It Works

Market lifecycle

Every market on FatTail follows this lifecycle:

1. Market creation

An admin or authorized user creates a market with:

A question (e.g., “Will BTC exceed $200K by March 2026?”)
An expiration date
Resolution criteria and oracle type
Initial probability skew (must be 90:10+)

2. Trading

Users buy shares on either side:

Yes shares — betting the event will happen
No shares — betting the event won’t happen

Prices are determined by the LS-LMSR automated market maker. As more capital enters one side, prices adjust accordingly.

3. Vig collection

Every trade generates a vigorish (vig) — a small spread that funds:

50% to the platform
50% distributed to yield seekers (dominant side holders, pro-rata)

4. Resolution

When the market closes, one of three oracle types determines the outcome:

Admin — platform operator resolves
Price Feed — automated from CoinGecko price data
Optimistic Oracle — community-driven propose/challenge/vote

5. Settlement

Winning shares pay out. Losing shares expire worthless. Settlement is recorded on-chain across all supported chains (Solana, Base, Arbitrum, Optimism, Polygon).

Deposits & Withdrawals

FatTail supports multiple deposit methods across 5 chains:

K-Points — Platform points credited on signup
Crypto wallet — Connect Phantom (Solana) or MetaMask/Rabby (EVM) and deposit USDC directly
Fiat on-ramp — Buy USDC with credit card or bank transfer via MoonPay on any supported chain

Withdrawals go back to the connected wallet on the same chain used for deposit.

Persona UI

FatTail offers two interface modes tailored to different trading styles:

Tail Mode — Multiplier-centric display. Shows potential 10x/50x/100x returns prominently. Purple-accented UI with Kelly calculator front and center.
Yield Mode — Probability-centric display. Shows dominant-side probability and APR. Green-accented UI with Vig earnings and yield tools prioritized.

Users can switch between personas at any time from the header.

FatTail includes a built-in referral system:

Referral codes — Every user gets a unique code. Earn 10% commission on referrals’ trading fees for 6 months.
Shareable cards — Share your position P&L or portfolio summary as a rich image (PNG download or OG-preview link).
Share flow — Every shared link includes ?ref=CODE, so anyone who signs up through your link automatically applies your referral.

See the Referral & Sharing page for full details.

Safety Guard

FatTail’s Safety Guard monitors probability drift. If prices move into the 11-89% range, a warning is displayed. This is informational only — trades are never blocked.