TWS API order types

This catalog covers every construction on IBKR's official TWS API Basic Orders page, then the major compound and algorithmic families. Availability is a function of product, route, region, account permissions, TWS/server version, and sometimes live versus paper trading. The final authority is the current IBKR order matrix plus ContractDetails.orderTypes/validExchanges.

Core directional orders

Name	Encoding	Operation and edge cases
Market	orderType="MKT"	Executes at available prices; favors immediacy, provides no price protection, and can sweep far through a thin book.
Limit	LMT; lmtPrice	Buy at limit or lower / sell at limit or higher. It may never fill. Price must conform to the applicable market-rule increment.
Forex cash quantity	usually LMT/MKT; cashQty	Sizes by settlement-currency cash rather than base units where supported. Do not also send a conflicting totalQuantity.
Market-to-limit	MTL	Sends as market; an unfilled remainder becomes a limit at the execution price. A partial first fill determines the remainder's cap.
Market with protection	MKT PRT	Futures-oriented protected market order; unfilled quantity becomes a limit at an exchange-defined protection price. Protection is not your chosen limit.
Limit with manual-order time	LMT; lmtPrice, manualOrderTime	Records the operator/manual submission time for reporting workflows. The timestamp is metadata, not an activation time; use goodAfterTime for activation. Server-version and institutional requirements apply.
Block	LMT; blockOrder=True	Large-block handling, historically ISE options specific. Size/routing eligibility is enforced by the venue.
Sweep-to-fill	LMT; sweepToFill=True	SMART-routed limit order that simultaneously addresses successive price levels for speed; never exceeds the limit.
Discretionary	LMT; lmtPrice, discretionaryAmt	Displays the limit while permitting a hidden discretionary range. Amount must obey tick precision; the hidden range changes execution economics.

Triggered orders

Name	Encoding	Operation and edge cases
Stop	STP; auxPrice=stop	On trigger becomes market. Trigger is not a guaranteed fill price; gaps can be severe. Buy stop normally lies above and sell stop below the market.
Stop limit	STP LMT; auxPrice=stop, lmtPrice=limit	On trigger becomes limit. Provides price protection but can remain unfilled after the market passes the limit.
Market if touched	MIT; auxPrice=trigger	Buy is normally triggered as market falls to/below the trigger; sell as it rises to/above. Semantically opposite to a protective stop.
Limit if touched	LIT; auxPrice=trigger, lmtPrice=limit	Touch activates a limit order. It can trigger and not fill.
Stop with protection	STP PRT; auxPrice=stop	Triggered futures order executes within an exchange protection band; remainder becomes a protected limit.
Trailing stop	TRAIL; auxPrice=absolute trail or trailingPercent; optional trailStopPrice	Favorable movement ratchets the stop; adverse movement does not. On trigger becomes market. Do not set competing trail amount forms.
Trailing stop limit	TRAIL LIMIT; trail amount/percent, lmtPriceOffset, optional trailStopPrice	Ratchets a trigger and, after trigger, submits a limit offset. Price protection introduces non-fill risk. Some TWS presets auto-populate offsets, so explicitly unset conflicting fields.
Adjustable stop family	parent plus triggerPrice, adjustedOrderType, adjustedStopPrice, adjustedStopLimitPrice, adjustedTrailingAmount	When the adjustment trigger is reached, modifies the parent into the specified stop/stop-limit/trailing type rather than transmitting a separate child. Do not confuse adjustment trigger with stop trigger.

Open, close, and auction

Name	Encoding	Operation and edge cases
Market on open	MKT, tif="OPG"	Participates in the opening process. Cutoffs and imbalance handling are venue-specific.
Limit on open	LMT, tif="OPG", lmtPrice	Opening participation with a limit; may not fill if the opening price violates it.
Market on close	MOC	Seeks the official close without user price protection. Venue cutoff/cancel rules are strict.
Limit on close	LOC; lmtPrice	Closing-auction order that fills only at a qualifying close price.
Auction	MTL, tif="AUC", lmtPrice	Entered before the open for the calculated opening price; official behavior may resubmit an unfilled remainder as a limit.
Auction limit	LMT; auctionStrategy	BOX option price-improvement auction participation with a limit. Direct routing and penny improvement rules apply.
Auction pegged to stock	PEG STK; delta, startingPrice, optional stock reference/range	BOX option auction price changes with the underlying by signed delta. Stock range can cancel the order.
Auction relative	REL; auxPrice=offset, auction fields	BOX option auction relative pricing. It is not the same as generic SMART pegged-to-primary behavior.
Imbalance-only	supported auction type plus imbalanceOnly=True	Participates only in supported exchange imbalance mechanisms; availability/cutoffs are route-specific.

Pegged and relative orders

Name	Encoding	Operation and edge cases
Pegged to market	PEG MKT; auxPrice=offset, optional cap	Maintains a price relative to the same-side market. Official examples and accepted token can vary by server/route; verify contract order types.
Pegged to primary	REL; auxPrice=offset, lmtPrice=cap	Buy follows NBB and sell follows NBO by offset, capped by limit. Can become aggressive as quotes move. Often unavailable in paper.
Passive relative	PASSV REL; auxPrice=offset	Pegged order designed to remain passive and avoid crossing; venue repricing rules determine behavior.
Pegged to midpoint	PEG MID; auxPrice=offset, lmtPrice=cap	Tracks NBBO midpoint with direction-sensitive offset and cap. Requires a valid NBBO and supported route.
Pegged to stock	PEG STK; delta/reference fields	Option price is pegged to movements in its underlying stock. Delta sign and option right matter.
Pegged to benchmark	PEG BENCH; referenceContractId, isPeggedChangeAmountDecrease, peggedChangeAmount, referenceChangeAmount, referenceExchangeId, lmtPrice	Price moves based on a reference contract's change from a reference value, not simply the traded contract's quote.
IBKR ATS pegged-to-best	PEG BEST; ATS fields such as minTradeQty, minCompeteSize, offsets	IBKRATS-only behavior. Routing, minimums, and whole/half-penny offsets are server-version dependent.
IBKR ATS pegged-to-mid	PEG MID with IBKRATS parameters	ATS midpoint behavior with venue-specific minimum and offset controls. Do not assume generic PEG MID parameters are interchangeable.
Midprice	MIDPRICE; optional lmtPrice cap	SMART-routed US-stock order that seeks NBBO midpoint or better. The optional cap is highest buy/lowest sell price; requires a valid NBBO and supported TWS/server version.

Venue-specific and volatility orders

Name	Encoding	Operation and edge cases
Box Top	BOX TOP	BOX option marketable order; unfilled remainder becomes a limit at the initial execution price. BOX route only.
Volatility	VOL; volatility, volatilityType, continuousUpdate, referencePriceType, optional lmtPrice and delta-neutral fields	Option order priced from implied volatility. Volatility type must be daily or annual as specified; underlying-price updates can reprice the order. Complex and entitlement-sensitive.
Scale	base order plus scaleInitLevelSize, scaleSubsLevelSize, scalePriceIncrement, and optional profit/reset fields	Breaks quantity into successively priced components. Invalid/missing level sizes and increments are rejected; fills alter subsequent levels.
Hedge	child order with parentId, hedgeType, hedgeParam	Creates supported delta/beta/FX/pair hedge behavior tied to a parent. Transmit sequence and account permissions are critical.

Combo orders

First create a Bag contract with ComboLeg records. Order-level forms are:

Name	Encoding	Meaning
Combo market	MKT	Market price for the combo where supported; legging and routing risk depends on native versus SMART handling.
Combo net limit	LMT; lmtPrice	Limit on net debit/credit. Confirm the sign convention in a paper account for the exact buy/sell leg construction.
Price per leg	LMT; orderComboLegs=[OrderComboLeg(price=...), ...]	Supplies leg prices. Number/order must match combo legs.
Relative limit combo	REL + LMT (official examples also show capitalization variants)	Relative behavior with an overall limit.
Relative market combo	REL + MKT	Relative combo without the same net limit protection.

SMART combo routing parameters use TagValue entries in smartComboRoutingParams; valid tags are venue/product specific. OCA support is restricted for SMART combos, and what-if calculations may be unavailable.

Compound order structures (not orderType tokens)

Bracket

IB.bracketOrder(action, quantity, limitPrice, takeProfitPrice, stopLossPrice) returns parent, take-profit child, and stop-loss child. The parent and first child have transmit=False; the last child has transmit=True, causing the group to transmit. Place all three in order. A process crash between sends can leave an untransmitted partial structure; reconcile it.

One-cancels-all

IB.oneCancelsAll(orders, ocaGroup, ocaType) assigns the group. Type 1 cancels remaining orders with block, type 2 proportionally reduces with block, and type 3 proportionally reduces without block. Partial fills and overfill risk differ. OCA is coordination, not a cross-venue atomic transaction.

Parent/child

Set child parentId to the parent's API order ID. Stage with transmit=False until the last intended child is ready. Child quantities should match supported parent rules, and children may remain held until the parent fills.

Algorithmic orders

Set algoStrategy and exact algoParams: list[TagValue]. Official sample tokens and parameters are:

Strategy	algoStrategy	Parameters shown by the official API sample
Adaptive	Adaptive	adaptivePriority (Urgent, Normal, or Patient)
Arrival Price	ArrivalPx	maxPctVol, riskAversion, startTime, endTime, forceCompletion, allowPastEndTime
Close Price	ClosePx	maxPctVol, riskAversion, startTime, forceCompletion
Dark Ice	DarkIce	displaySize, startTime, endTime, allowPastEndTime
Accumulate/Distribute	AD	componentSize, timeBetweenOrders, randomizeTime20, randomizeSize55, giveUp, catchUp, waitForFill, activeTimeStart, activeTimeEnd
Percentage of Volume	PctVol	pctVol, startTime, endTime, noTakeLiq
TWAP	Twap	strategyType, startTime, endTime, allowPastEndTime
VWAP	Vwap	maxPctVol, startTime, endTime, allowPastEndTime, noTakeLiq, speedUp
Price Variant % Volume	PctVolPx	startPctVol, endPctVol, startTime, endTime, noTakeLiq, speedUp
Size Variant % Volume	PctVolSz	startPctVol, endPctVol, startTime, endTime, noTakeLiq
Time Variant % Volume	PctVolTm	startPctVol, endPctVol, startTime, endTime, noTakeLiq
Balance Impact Risk	BalanceImpactRisk	maxPctVol, riskAversion, forceCompletion
Minimize Impact	MinImpact	maxPctVol

Some official regional examples use maxPctVol4Px, minPctVol4Px, or deltaPctVol. Treat the tag set as a schema: values are strings, booleans are normally encoded as "1"/"0", percentages have strategy-specific ranges, and an unknown/misspelled tag is not safely ignored.

Do not invent tags. Use the current official IB algorithms reference. Common parameters include start/end time, participation percentage, urgency/risk aversion, allow-past-end-time, force completion, and component/display size. Time parameters must be in the future where required (for example, error 167 for a past VWAP start).

Conditions

Conditions do not create new order types. Append PriceCondition, TimeCondition, MarginCondition, ExecutionCondition, VolumeCondition, or PercentChangeCondition to Order.conditions, link with .And()/.Or(), and control behavior with conditionsCancelOrder and conditionsIgnoreRth.

A price condition needs a canonical conId, exchange, trigger price, and comparison direction. A condition can be satisfied during a data gap or based on a trigger method you did not intend; test both RTH settings. Conditions are unavailable for some contracts/order types.

Official sources: basic orders, order conditions, IB algorithms, and IBKRATS orders.