Glossary

This page collects plain-English definitions of terms used across BULK Exchange. For formal specifications, see the linked pages on docs.bulk.trade.

Trading mechanics[edit]

Maker / Taker: A maker order adds liquidity to the order book (it rests instead of filling immediately). A taker order removes liquidity by matching against a resting order. BULK currently waives maker fees during its Genesis Liquidity phase and charges takers a small fee that scales down at higher volume tiers. See Fees on BULK.

GTC / IOC / ALO

Time-in-force settings that control how long an order can rest before it's cancelled.

GTC (Good-Til-Cancelled) — the default. Rests on the book until filled or manually cancelled.
IOC (Immediate-Or-Cancel) — fills whatever is immediately available, cancels the rest.
ALO (Add-Liquidity-Only / post-only) — rejected outright (as `rejectedCrossing`) if it would immediately cross the book, guaranteeing it always fills as a maker order. Note: BULK's WebSocket feed reports this order type as `"postOnly"` on the wire, even though the internal name is ALO.

Reduce-Only: An order flag that clamps the order's size so it can only shrink your existing position, never flip it or open a new one in the opposite direction.

Mark Price: The reference price used to calculate unrealized P&L and trigger liquidations. On BULK it's a blend of the oracle price (adjusted for BULK's own book premium), the order book's median price, and a smoothed local price — not simply the last traded price, which makes it harder to manipulate with a single large trade.

Self-Trade Prevention: BULK's matching engine checks whether an incoming order and a resting order belong to the same account. If they match, the engine skips that resting order (without cancelling it) and keeps looking for other liquidity, rather than letting you accidentally trade against yourself.

Portfolio Margin: BULK's margin model evaluates your entire portfolio as one unit, accounting for correlation between your positions, instead of adding up margin requirements position-by-position. A hedged portfolio (e.g. long BTC perp and short ETH perp, given how correlated those two assets tend to be) can require significantly less margin than the same positions held in isolation — BULK's documentation cites a 30–70% margin reduction for a correlated hedge like that at 10x leverage. See Understanding Portfolio Margin for a walked-through example.

Isolated Margin: The alternative to portfolio margin: collateral for a single position is walled off in its own sub-account (created automatically when you set the isolate flag on an order), so a liquidation there can't touch your other positions — but you also lose the correlation benefit that portfolio margin gives you.

Sub-Account: A separate trading account under your main wallet (up to 64 per wallet), each with its own independent portfolio margin, positions, and orders. Liquidation in one sub-account has no effect on your master account or your other sub-accounts.

Maintenance Margin: The minimum equity you must hold against an open position before it's at risk of liquidation. On BULK this isn't a single fixed percentage — it moves with your leverage, how much moving the market to close your position would cost (liquidity impact), and current market volatility regime.

Liquidation: The forced reduction or closure of a position when your account equity falls below the maintenance margin requirement. BULK tries partial, incremental reductions first (sized to how severe the shortfall is) before resorting to closing the position entirely. See How Liquidations Work.

Auto-Deleveraging (ADL): A last-resort mechanism used only when a liquidation can't be filled normally — either because losses exceeded available collateral (a "shortfall") or the position couldn't be reduced fast enough (an "underfill"). In that case, BULK reduces the positions of profitable traders on the other side of the trade, prioritized by profit and leverage, to make up the difference. See the full breakdown for how selection, pricing, and the protocol risk vault actually work.

Funding Rate: An hourly payment between long and short position holders on a perpetual contract, designed to keep the contract's price tethered to the underlying spot price. If funding is positive, longs pay shorts; if negative, shorts pay longs. The payment flows directly between traders — BULK doesn't take a cut of funding payments.

BULKBFT: The leaderless Byzantine fault-tolerant consensus protocol that BULK's validator network uses to agree on order matching and execution, running alongside (not instead of) Solana's own consensus.

Fair Ordering: BULK's set of mechanisms to prevent trade reordering, front-running, and censorship — including requiring a transaction to be seen by a quorum of validators before it's eligible for matching, and a deterministic shuffle (rather than validator discretion) to decide execution order within a batch.

Taker Speed Bump: A temporary (documented as lasting the first 90–120 days after launch) 25-millisecond minimum delay applied to any transaction that could take liquidity, giving resting maker orders a brief window of protection. Post-only (ALO) orders are exempt and execute immediately.

Access Code: BULK's mainnet is currently invite-only. New accounts need an access code to sign up — see Getting Started for how to get one.