Central Limit Order Book (CLOB)

6.1 Rationale for a CLOB Architecture

Parallelshots adopts a Central Limit Order Book rather than an automated market maker in order to achieve explicit price discovery, reduced slippage under size, and compatibility with professional trading strategies. In memecoin markets, where liquidity is often discontinuous and volatility is extreme, AMM-based curves introduce nonlinear execution costs and reflexive price distortions. A CLOB provides discrete pricing, transparent depth, and strict execution ordering, all of which are critical for leveraged trading systems. The CLOB is implemented as a logical construct maintained by the matching engine, while its economic effects are enforced by on-chain settlement. The blockchain remains the system of record for balances, margin, and positions, while the order book itself is treated as ephemeral state that can be reconstructed from signed orders and execution events.

6.2 Order Book Structure

For each market m, the order book is defined as two priority queues:

Bids[m] := max-heap ordered by (price DESC, time ASC)
Asks[m] := min-heap ordered by (price ASC, time ASC)

Each price level may contain multiple orders sorted by submission timestamp. An order is defined as:

Order {
  order_id: uint64
  trader: address
  market_id: uint32
  side: {BUY, SELL}
  price: uint256
  quantity: uint256
  remaining_quantity: uint256
  leverage: uint8
  timestamp: uint64
}

Orders are immutable after submission except for remaining_quantity.

6.3 Price-Time Priority Enforcement

Execution priority is strictly defined as:

Primary key: better price
Secondary key: earlier timestamp

Formally, for two orders o1 and o2 on the same side:

o1 precedes o2 if:
  (o1.price > o2.price) OR
  (o1.price == o2.price AND o1.timestamp < o2.timestamp)

No discretionary reordering or batching is permitted.

6.4 Matching Conditions

A match is executable when:

best_bid.price ≥ best_ask.price

Execution proceeds iteratively:

while best_bid.price ≥ best_ask.price:
    exec_price = resting_order.price
    exec_qty   = min(bid.remaining_qty, ask.remaining_qty)

    emit Trade(market_id, bid_id, ask_id, exec_price, exec_qty)

    decrement remaining quantities
    update order states

The resting order defines the execution price to prevent price manipulation by aggressive orders.

6.5 Market Orders

Market orders are represented internally as limit orders with extreme price bounds:

BUY market order  → price = +∞
SELL market order → price = 0

They consume available liquidity until fully filled or until margin constraints are violated.

6.6 Risk-Gated Order Admission

Before insertion into the order book, each order must satisfy:

initial_margin_required :=
  (price * quantity) / leverage

require(
  free_margin(trader) ≥ initial_margin_required,
  "MARGIN_INSUFFICIENT"
)

Orders failing pre-trade checks are rejected and never enter the book.

6.7 On-Chain Settlement Interface

Each executed trade is settled via a canonical interface:

function settleExecution(
  uint32 marketId,
  address maker,
  address taker,
  uint256 price,
  uint256 quantity
) external onlyEngine;

Settlement updates:

Position size
Average entry price
Locked margin
Unrealized PnL

The CLOB itself cannot mutate balances.

6.8 Failure and Recovery Guarantees

If the matching engine halts:

No orders are lost
No balances are affected
On-chain state remains authoritative

The order book can be reconstructed deterministically from signed orders and executed trades.

Getting started

Technicals

Market Structure

Liquidity

Central Limit Order Book (CLOB)

6.1 Rationale for a CLOB Architecture

6.2 Order Book Structure

6.3 Price-Time Priority Enforcement

6.4 Matching Conditions

6.5 Market Orders

6.6 Risk-Gated Order Admission

6.7 On-Chain Settlement Interface

6.8 Failure and Recovery Guarantees

​6.1 Rationale for a CLOB Architecture

​6.2 Order Book Structure

​6.3 Price-Time Priority Enforcement

​6.4 Matching Conditions

​6.5 Market Orders

​6.6 Risk-Gated Order Admission

​6.7 On-Chain Settlement Interface

​6.8 Failure and Recovery Guarantees

6.1 Rationale for a CLOB Architecture

6.2 Order Book Structure

6.3 Price-Time Priority Enforcement

6.4 Matching Conditions

6.5 Market Orders

6.6 Risk-Gated Order Admission

6.7 On-Chain Settlement Interface

6.8 Failure and Recovery Guarantees