What this is
Callio is a marketplace for options on Robinhood Chain. One person sells an option and another buys it, directly from their own wallets. There's no company in the middle holding your money, and no margin or liquidations.
Two rules make it work:
- Fully backed. A seller locks their whole side in the contract before their listing appears, so the buyer never depends on the seller paying later.
- Real delivery. Using an option swaps real tokens for real tokens at the agreed price. No outside price feed decides anything.
Getting set up
You need three things:
- A wallet that works with Robinhood Chain, such as MetaMask or Rabby.
- A little ETH on Robinhood Chain for network fees. These are usually a tiny fraction of a cent to a few cents.
- USDG to pay for options, or the token you want to sell an option on.
On a computer
Use a browser with your wallet extension installed, such as Chrome or Brave. Press Connect and choose your wallet. If it asks to add or switch to Robinhood Chain, approve that.
On a phone, or in Safari
Press Connect, then WalletConnect, and pick your wallet. On a computer you can scan the QR code with your wallet app instead. You can also open this site in your wallet app's own browser, which connects directly.
Network details, if you need to add it by hand
- Network
- Robinhood Chain
- Chain ID
- 4663
- Currency
- ETH
- RPC
- https://rpc.mainnet.chain.robinhood.com
- Explorer
- https://robinhoodchain.blockscout.com
Options in plain words
An option is the right, but not the duty, to trade a token at a fixed price until a set time. That fixed price is the strike, the end time is the expiry, and what you pay for the right is the premium.
- Call: the right to buy at the strike. You want the price to go up.
- Put: the right to sell at the strike. You want the price to go down.
Example: a call
You think it goes upA token trades at $100 and you think it will rise. You pay a $5 premium for a call with a $110 strike on 1 token.
| It ends at | What you do | Result |
|---|---|---|
| $130 | Exercise: pay $110, get a token worth $130 | +$15 |
| $112 | Exercise: you get $2 back of your $5 | −$3 |
| $100 | Don't exercise, it ends unused | −$5 |
Example: a put
You think it goes downA token trades at $100 and you think it will fall. You pay a $5 premium for a put with a $90 strike on 1 token.
| It ends at | What you do | Result |
|---|---|---|
| $70 | Exercise: hand over a $70 token, get $90 | +$15 |
| $88 | Exercise: you get $2 back of your $5 | −$3 |
| $100 | Don't exercise, it ends unused | −$5 |
Examples are before fees, and the prices are made up. On the site, the payout simulator draws this for the real option you're looking at.
Buying an option
- On Trade, pick a token and choose whether you think it goes up or down.
- Pick a price level, then a date. A level with no seller can't be bought yet.
- Read the payout simulator, which shows your result at any final price.
- Press Buy and approve in your wallet. The first time with a token, your wallet asks for permission first, then for the purchase.
The premium goes to the seller straight away and can't be refunded. Your option then appears in Portfolio.
Exercising
You can exercise at any time until the moment the option ends. Open it from Portfolio and press Exercise.
- Call: you pay the strike in USDG, plus the exercise fee, and receive the tokens.
- Put: you hand over the tokens and receive the strike, less the exercise fee.
Nothing exercises by itself. An option that's in profit but not exercised before it ends is worth nothing, so don't leave it to the last second. You also need the USDG or tokens in your wallet at that moment.
If exercising would lose money, the site warns you first. You can still go ahead.
When an option ends
At expiry an unused option is finished. The seller's locked tokens go back to them and the buyer has nothing more to do. Anyone can trigger this, and our robot normally does it within a few minutes, so sellers don't need to do anything.
The option doesn't go back on sale. To sell again, create a new listing.
Selling an option
Selling earns the premium up front, in exchange for taking on the other side.
- On a token, choose Sell, then what you think won't happen.
- Set the strike, the size, the end date and your premium.
- Check the review screen, then approve. Your side locks and the listing appears.
- Selling a call locks the tokens. If the buyer exercises, you get the strike in USDG instead.
- Selling a put locks the strike in USDG. If the buyer exercises, you get the tokens instead.
What a seller's result looks like
It's the buyer's chart flipped over. Here's the seller of the $110 call from earlier: you keep the $5 unless the price passes the strike, then you give up the gain above it.
And the seller of the $90 put: you keep the $5 unless the price falls below the strike, then you end up buying the token above its market price.
Until someone buys, you can edit or cancel and get everything back. After a sale your side stays locked until the option is exercised or ends.
When a buyer exercises, your payment waits in that option's vault. Open the listing and press Claim to collect it.
Bids
Instead of paying the asking premium, a buyer can bid lower. The bid is held in escrow and the seller can accept it at any time before it runs out, which fills the option at that price.
You can withdraw your bid whenever you like. If the seller edits the listing, bids on the old terms can't be accepted, and only get returned.
Passing on a position
A buyer can transfer an option to another wallet before it ends, and that wallet then holds the right to exercise it. Transfer has no payment built in, so only send it to a wallet you trust or own.
Fees
- Premium fee
- 2% of the premium, taken from what the seller receives
- Exercise fee
- 0.25% of the strike, only if the option is exercised. It's fixed when the option is bought
- Letting an option end
- Free. We pay the network fee to settle it
- Network fees
- Paid in ETH to Robinhood Chain for every transaction
- Limits
- The contract can never charge more than 5% of the premium or 0.5% of the strike
Swapping tokens elsewhere to get USDG has its own costs, which aren't ours.
Prices and fair value
Sellers set their own premiums, and the contract never reads a price. The USD prices you see come from outside data, and they're for information only.
The fair value label is a standard estimate based on how much the token has been moving, with a confidence rating. Treat it as a rough guide, not a quote. If we can't find a price, we show “no price” rather than guess.
- High confidence
- Verified token with 30 days of price history
- Medium
- At least 7 days of history
- Low
- Less history, or no price source
Token warnings
Anyone can create a token, and anyone can list an option on any token, so check what you're trading.
- Copies: a fake can use a real token's name and logo. Check the contract address, and look for the Verified mark.
- Issuer controls: some tokens can be paused or frozen by their issuer. Robinhood stock tokens can, and a pause before an option ends could block exercising it.
- Safety facts: token pages show what a scan found. A clean scan isn't a guarantee.
Risks
Please read this before trading. Only use money you can afford to lose.
- Early software. This is a private beta. The contract has had automated reviews but no professional audit yet, and it can't be changed once deployed, so a bug could lose funds.
- Buyers can lose the whole premium, and it's easy to miss the end time.
- Sellers can miss out. You keep the premium, but if the price moves against you, you deliver at the strike however far it has moved.
- Old listings can go stale. A listing keeps its terms as the market moves, and someone may buy it the moment it's a bargain. Review or cancel listings you're not watching.
- Wallet permissions. Approvals let the contract move a token from your wallet when you trade. Review them with your wallet if you stop using the site.
- Tokens themselves can fall to zero, be paused, or stop being tradable.
Nothing here is financial advice, and we don't hold your funds or reverse transactions.
Questions
My wallet won't connect on my phone.
Use WalletConnect, or open the site in your wallet app's browser. If your wallet can't add Robinhood Chain, add it by hand with the details above.
Why do I see two wallet popups?
The first time you use a token, your wallet asks for permission to spend it, then for the trade itself.
I sold an option and nobody bought it.
It stays listed until it ends, or until you cancel. Either way you get your tokens back.
Someone bought my option but didn't use it.
You keep the premium, and your tokens come back when it ends, normally within a few minutes.
Can I sell an option I bought?
There's no market for that yet. You can pass it to another wallet, but payment would have to be arranged separately.
My invite code doesn't work.
A code works on 2 devices or browsers, and your wallet app's browser counts as one. Once you're in, that device won't ask again. If it has run out, ask for a new one.
Contract details
The contract can't be upgraded, and its source code is public, so anyone can check what it does. The admin can change fees within the limits above, the fee wallet, the accepted payment tokens and the allowed option lengths, but has no way to move, freeze or pause anyone's funds.
Each listing keeps its locked tokens in its own vault, never pooled with anyone else's.
- Network
- Robinhood Chain (chain ID 4663)
- Explorer
- https://robinhoodchain.blockscout.com