Aarka

Aarka - split a tokenized stock into a Floor and the Upside.

A tokenized stock can only be held or sold. What stock holders actually do with options sell the growth they don't expect for cash today, or buy the growth they do expect for a fraction of the price needs an option writer, margin and liquidations. On-chain, almost nobody does it.

WHAT AARKA DOES :

Aarka splits one share into two tokens at a fixed price line and end date:

• Floor — keeps the stock's value up to the line. Pays min(P, K) / P of a share.

• Upside — gets everything above the line. Pays max(P − K, 0) / P of a share.

• Floor + Upside = exactly one share, at every price. The vault is always fully solvent, with no counterparty.

• • Always reversible. One Floor plus one Upside turns back into one share, any time, even after the end date.

• • Nothing to liquidate. Nobody borrows anything, so nobody can be force-sold.

Keep one, sell the other:

• Earn cash on my shares — keep the Floor, sell the Upside, in one transaction.

• Bet on a rise — buy the Upside for a fraction of a share

HOW IT WORKS:

1. Settlement

On the end date, anyone calls settle(roundId). The contract proves it is Chainlink's last price at or before the close (no more than 26 hours old, no later round), checks the L2 sequencer and corporate-action guards, then allows a one-hour challenge. A 7-day late path means every split always resolves. You are paid in the stock itself.

2. Parity hook (Uniswap v4)

Each half trades against USDG on Uniswap v4. Our afterSwap hook watches Floor + Upside against the share. If they drift more than 1%, it finds the exact trade size, splits or rejoins shares against the vault inside the same transaction, and gives the profit to liquidity providers. A failed arbitrage can never break the user's swap.

3. Router

"Keep the Floor, sell the Upside" happens in a single transaction.

PROVEN ON ROBINHOOD CHAIN TESTNET:

Using the real mainnet Chainlink prices, mirrored with their timestamps:

• 11 splits settled against real Chainlink closing prices.

• The hook restored parity live after a $50,000 trade, paying $1,246 to liquidity providers in the same transaction ($3,655 across all restorations).

• Every user action tested end to end: split, rejoin, buy, sell, split-and-sell, settle, collect.

SECURITY :

• 213 unit, fuzz and invariant tests, 99% line coverage.

• Fork tests against Robinhood Chain mainnet.

• Four review rounds, 29 findings, each with a test that reproduces it.

• All 71 contracts verified on the explorer.

• No proxies, no upgrades, no admin over funds, no price override.

BUILT WITH Robinhood Chain (Arbitrum Orbit)

· Chainlink · Uniswap v4 · Solidity · Foundry · Next.js

LINKS :
Live app: https://aarka-app.vercel.app
How it works: https://aarka-app.vercel.app/how
GitHub: https://github.com/Madhav-Gupta-28/Aarka