edgeX Modify & Chase Orders: Managing Open Limit Orders as the Market Moves

IntermediateNov 9, 2026 · 6 min read

Modify is for precision; Chase is for speed. Use Modify when you want to choose the exact new limit price or remaining quantity.

Key points

Modify is the precision tool: set a new limit price or remaining quantity for an open edgeX perpetuals order.
Chase is the faster repricing tool: move the unfilled portion closer to the latest order book when the market has moved away.
After a partial fill, only the remaining quantity is still open; completed fills stay part of your position.
A closer limit can improve the chance of matching, but neither Modify nor Chase guarantees execution.
Before and after any change, check the live price, filled quantity, remaining quantity, order status, and resulting position.

Short Answer

Modify is for precision; Chase is for speed. Use Modify when you want to choose the exact new limit price or remaining quantity. Use Chase when the price has moved away and you want to bring the unfilled portion closer to the latest order book in fewer steps. Both actions preserve limit-price control, work only on what remains open, and still require you to verify the final order.

What Are Modify and Chase?

Control	Core job	What you decide	What stays true
Modify	Edit an open order directly	The exact new limit price or remaining quantity	Completed fills do not change
Chase	Reprice the unfilled portion toward the latest order book	Whether to bring the order closer to the active market	The updated order remains price-limited

Modify and Chase replace a longer manual sequence: cancel the open order, enter revised details, and submit another order.

They are not the same action with different names. Modify gives you direct control over the new values. Chase is the quicker choice when the main problem is that the resting price has fallen behind the latest book.

Why You Need Them

An open limit order can become outdated before it fills.

The best bid and ask may move away from your price. Part of the order may execute while the rest remains open. Your intended position size may also change.

These situations create three different decisions:

The price is wrong: choose a new limit with Modify.
The open size is wrong: change the remaining quantity with Modify.
The order has drifted away from the market: use Chase to reprice the unfilled portion faster.

The controls shorten order management, but they do not remove the basic limit-order tradeoff. You retain a price boundary; you do not gain a fill guarantee.

How Modify Works

1. Read the current order, not the original instruction

Start with the order’s live state: filled quantity, remaining quantity, current limit price, and status.

2. Choose the field that needs to change

Modify lets you set:

a new limit price; or
a new quantity for the unfilled portion.

A price edit changes where the remainder may execute. A quantity edit changes how much is still working.

3. Separate completed fills from the open remainder

If 4 of 10 contracts have filled, 4 are already part of your position and 6 remain open. A remaining-quantity edit applies to those 6 contracts, not to the original 10 and not to the 4 completed fills.

4. Submit the change and confirm it

After the modification, read the updated order row again. The displayed limit price and remaining quantity are now the values that matter.

How Chase Works

1. Confirm that price drift is the real problem

Chase is useful when the order is still open but its limit has moved away from the latest order book.

2. Chase the unfilled portion

The action moves the remaining order closer to the current book without requiring you to rebuild it manually.

3. Keep the limit-order tradeoff in view

Moving closer can improve the chance of matching. It does not promise a fill: the book can move again, available quantity can change, and other orders can match first.

4. Read the new limit price

After Chase, use the price shown on the updated order. The quote visible just before the action was only a snapshot.

Worked Example: 4 Filled, 6 Still Open

Assume you submit a buy limit order for 10 contracts at 100.00.

Four contracts fill. The order now shows:

Order field	Current value
Original quantity	10 contracts
Filled quantity	4 contracts
Remaining quantity	6 contracts
Current limit price	100.00

The market then moves to a best bid of 100.20 and a best ask of 100.30. The latest ask is 0.30 above the original limit, equal to 0.30% or 30 basis points in this illustration.

The order now has two parts:

4 completed contracts that already affect your position.
6 open contracts whose limit price or remaining size can still change.

If you choose Modify

You can set an exact new buy limit, such as 100.20. If you no longer want all 6 open contracts, you can instead reduce the remaining quantity to 3.

The 4 completed contracts stay completed.

If you choose Chase

You can move the 6 open contracts closer to the latest book in fewer steps. Afterward, check the limit price edgeX displays rather than assuming it matches the quote you saw before acting.

The example does not make one choice automatically better. Modify fits a precise target. Chase fits faster repricing.

When to Use Which

Situation	Better starting choice	Decision insight
You know the exact price you want	Modify	Set the price deliberately
You need to change how much remains open	Modify	Recalculate from the unfilled quantity
The market has moved away and the order is now stale	Chase	Bring the remainder closer to the latest book faster
A partial fill changed the position you still want	Modify	Resize the remainder to fit the updated plan
You are unsure whether the original trade still makes sense	Neither yet	Reassess before moving the order

Use Modify when the answer is a specific value. Use Chase when the answer is faster repricing. If the trading idea itself has changed, do not treat Chase as an automatic next step.

Risks & Best Practices

The book can move while you act

The bid, ask, and available quantity may change between the moment you read the book and the moment the updated order is active. Always verify the live result.

Closer does not mean guaranteed

The updated order remains a limit order. For a buy, the limit is the highest price you will pay; for a sell, it is the lowest price you will accept. A better position in the book can improve execution probability without ensuring execution.

Partial fills change the arithmetic

Base quantity decisions on what remains open. Editing as if the original quantity were still outstanding can leave you with a larger or smaller final position than intended.

Repricing can change the trade

A limit chosen earlier may have represented a deliberate entry or exit. Repeatedly moving it because the market moved can weaken that original boundary.

Common mistakes

Mistake	Why it matters	Better practice
Editing from the original quantity	Some contracts may already be filled	Start from filled and remaining quantities
Treating Chase as a fill guarantee	The market and available depth can move again	Verify the updated order and wait for the actual status
Assuming the new limit from the earlier quote	The book is a live snapshot	Read the limit price displayed after the action
Chasing whenever price moves	The revised order may no longer fit the trading plan	Reconfirm the acceptable price before acting
Ignoring the position after a partial fill	Completed fills already changed exposure	Check the current position with the order state

For the underlying screen mechanics, see What Is an Order Book?, What Is Depth of Market?, and What Is Spread?.

Decision Checklist

Before you act

[ ] Is the order still open, and is the displayed status current?
[ ] How much has filled, and how much remains open?
[ ] If the entire remainder fills, will the resulting position still fit my plan?
[ ] Do I need an exact new price or size? If yes, use Modify.
[ ] Is price drift the only problem, with the trade still valid? If yes, consider Chase.
[ ] Does the new limit still represent the highest acceptable buy price or lowest acceptable sell price?
[ ] Have I checked the latest bid, ask, spread, and nearby depth?

After you act

[ ] Did the limit price update to the value now shown?
[ ] Is the remaining quantity what I intended?
[ ] Did any additional quantity fill while I was making the change?
[ ] Is the final order status open, partially filled, filled, or canceled?
[ ] Does the current position match the exposure I now want?

The decision is complete only when the updated order and the current position agree with each other.

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Disclaimer

This content is for educational purposes only and does not constitute investment advice. Trading digital assets and derivatives involves risk. Make sure you understand the products and consider your own circumstances before trading.

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