- Buying
- Selling
Browse to a market and select an outcome
Find a market using
/markets, /sports, a keyword search, or a pasted Polymarket URL. On the market card, tap the outcome you want to buy — for example, Yes or Lakers to win.Choose an amount
You’ll see preset buttons — 25, and to enter any amount. The minimum is $1.00.Before you confirm, Overdog checks the live orderbook to calculate your real fill price and estimated shares.
Review the confirmation
The confirmation screen shows:
If the orderbook price differs from the mid-price, both are shown so you know exactly what to expect.
| Field | Description |
|---|---|
| Outcome | What you’re buying |
| Fill price | Estimated average price from the orderbook |
| Shares | Estimated shares you’ll receive |
| Total | Dollar amount you’re spending |
| Fee | 1% of your total (deducted from the trade amount) |
If the orderbook shifts between when you review and when you confirm, the Fill-or-Kill order may not be filled. You’ll see a “Price moved too fast” message and can tap Retry to try again with fresh pricing.
Slippage and pricing
Overdog walks the live orderbook to calculate your fill price before you confirm. This means the price shown reflects the actual depth of the market, not just the mid-price. The default slippage tolerance is 3%. If the final execution price would exceed this threshold, the Fill-or-Kill order is rejected and you can retry.Sell All
From/positions, tap Sell All to close every open position at once. You’ll see a confirmation before anything is submitted. Positions with wide bid-ask spreads are flagged so you can decide whether to include them.