Introduction

Lull executes orders for xStocks at the US market open. You place an order while the market is closed. It stays sealed until shortly before the open. Then it crosses once, together with every other order, at P_open: the first verified price of the underlying stock that Pyth publishes after the regular session opens.

Lull runs one market per xStock. The first is AAPLx/USDC. AAPLx is the xStocks token for Apple, and its open price comes from Pyth's Equity.US.AAPL/USD feed.

Why trade at the open#

xStocks trade on Solana around the clock. The stocks underneath them trade only in the US regular session, 09:30 to 16:00 ET on weekdays. That is 32.5 of the week's 168 hours. The rest of the week is a lull. Pools are thin and spreads widen. Anyone who sees a sell imbalance on a Saturday can push a thin pool, or position on another venue, before Monday.

Brokerages handle this with an opening auction and two order types, market-on-open (MOO) and limit-on-open (LOO). Lull gives a self-custody wallet the same order types. It defers execution to the official open and keeps the order queue sealed until just before it.

The flow in brief#

1. Deposit. Move USDC or AAPLx into your balance for the market. You can deposit and withdraw free balance at any time.
2. Seal. During the lull, seal an order on the "Order ticket". Only a hash of the order (its commitment) and a SOL bond go on chain. No tokens move, and nothing about the order is public.
3. Reveal. In the reveal window before the open (open − 30 min to open − 1 min by default), reveal the order. The program checks it against the commitment and locks the amount in your balance.
4. Cross. Just after the open, P_open is captured and the revealed book crosses at it. Buys and sells match at P_open. Liquidity providers (LPs) absorb the remaining imbalance with sealed spread quotes, cheapest first.
5. Claim. Your fill and any unfilled remainder go to your free balance, and your bond returns to your wallet. You withdraw when you choose.

A sealed order that is never revealed forfeits its bond. If no valid price arrives in time, the lull is cancelled and every revealed order is refunded in full.

Who holds what#

• Your wallet signs every transaction. The app never holds keys.
• The random salt that seals your order is generated and stored in your browser. The service never receives it before your reveal lands on chain.
• Deposited tokens sit in the market's vault, which belongs to the market's program address. Only the program's rules move tokens out of it, and your free balance leaves only when you withdraw it. The market authority cannot move user funds. The AAPLx issuer's own token controls are the exception, described in Risks.

Next#

• Quick start walks through a first order.
• Lulls explains the calendar and the phases.
• Sealed orders covers what is hidden and when it becomes public.
• The cross shows the matching step by step.
• Risks lists what can go wrong.