What You'll Learn
The order types available on TopstepX and how each one fills
Why your fill price and your order price can be different
What slippage is and the market conditions that cause it
The Basics
Order types control how and when your trades fill. Slippage is what happens when the market moves between your order and your fill. It can work in your favor, or against you.
Order Types
All order types below are available on TopstepX™.
Order Type | How It Works |
Market | Fills at the best available price. Prioritizes getting filled — the exact fill price can vary, especially in fast or thin markets. |
Limit | Buy below market or sell above. Sets the price you're willing to accept, but the order isn't guaranteed to fill. |
Stop Market | Becomes a market order when stop price is hit. Buy Stop = above market. Sell Stop = below. |
OCO (One Cancels Other) | 2 orders linked. When 1 fills, the other cancels. Used as a bracket. |
Market Orders
Market Orders
Executes at the next available price. No price specified; you get the best fill available when your order hits the exchange. Use it when getting filled matters more than the exact price. Fastest way in or out.
Limit Orders
Limit Orders
Sets the maximum price you will pay to buy or the minimum price you will accept to sell. Limit buys go below the current price. Limit sells go above it.
This is best when getting your exact price matters more than speed. The trade-off: the market has to trade through your price — not just touch it. You might not get filled. Partial fills happen. Order stays in the book until it's filled, canceled, or expired.
Stop Orders
Stop Orders
Triggers at your stop price, then executes like a market order — best available fill. Buy stops go above current price. Sell stops go below it. Once the stop price is triggered, you're in at whatever the market gives you. No price guarantee. Slippage can happen.
OCO
OCO
Two orders linked. One fills, the other cancels. Primarily used as bracket orders, a stop and a limit wrapping your position, helping manage your exit once it's set.
Slippage
Slippage is the difference between the price you expected when you placed your order and the price you actually got when it filled. It happens because market orders are designed to prioritize speed over price and execute immediately at the best available price, rather than waiting for your exact target.
This applies whether the order was placed manually, triggered by a stop, or executed by an automated risk-management system. In each case, the order fills at the best available price at that moment, which may differ from the last traded price or the price displayed when you submitted the order.
If the size you want isn't sitting at the top of the order book, the exchange moves down to the next price level (or several) to find the remaining volume. That can result in staggered fills across multiple prices, which is one of the most common ways slippage shows up in fast-moving markets.
Slippage occurs specifically when a market order, whether placed manually, triggered by a stop, or executed by an automated risk-management system, fills at a price different from what the trader expected to pay, not necessarily the last traded price. When a client places a buy market order, they expect to fill at or near the ask; when placing a sell market order, they expect to fill at or near the bid. That's because a market order prioritizes speed over price: it instructs the exchange to fill immediately at the best available price, and if the size you want isn't sitting at the top of the order book, the exchange moves down to the next price level (or several) to find the remaining volume, resulting in staggered fills across multiple prices.
Common slippage triggers
Economic releases
High volatility periods
Illiquid markets
Swing highs/lows (Price often accelerates sharply through these levels as stop orders cluster nearby and get triggered in a rush, pulling liquidity away from that price point)
Market open and close
Slippage Isn't Limited to Manual Trades
Slippage can affect any market order, regardless of what triggered it. Stop orders convert to market orders once triggered, and orders triggered by automated risk-management tools, or other broker-side safeguards that force a position closed, including forced or auto-liquidation, execute the same way: they accept whatever price the market offers to close the position immediately. This matters for risk planning, since a forced liquidation does not get special price protection just because it was not manually placed.
What causes slippage
Three main drivers: volatility, liquidity, and market gaps.
Volatility — Fast markets create a lag between when you place an order and when it fills. Economic releases, unexpected events, and sharp moves can all push your fill price away from your order price. Note: in fast-moving markets, exchange safeguards like CME Velocity Logic can also pause trading when liquidity can't keep pace with the speed of price moves. Learn more.
Liquidity — Fewer buyers and sellers means it's harder to fill at a specific price. The market adjusts to absorb your order size, and that adjustment shows up in your fill.
Market gaps — News hits while the market is closed. It reopens at a different level. Your resting orders fill at the next available price, not where you expected.
How to Manage Slippage
These methods do not guarantee results, but can help you navigate slippage:
Use limit orders where possible.
A limit order lets you set the maximum price you will pay to buy or the minimum price you will accept to sell. You may not always get filled but you avoid unexpected execution prices.
Be aware of market conditions.
Slippage is more likely during economic releases, market open and close, and low-liquidity periods. Know what is on the calendar before you trade.
Size your orders appropriately.
Larger orders may be harder to fill at a single price. Breaking a large position into smaller orders reduces the risk of an unexpected fill price, since smaller orders are less likely to get filled at several different prices as they work through the market.
FAQ
Does a limit order guarantee my price? A limit order guarantees you will not receive a worse price than your limit, but not that the order will fill. The market has to trade through your limit price first.
Can slippage happen on a market order? Yes, and it is most common with market orders. A market order prioritizes getting filled over getting a specific price. In fast or volatile markets, the price can move between when you place the order and when it executes.
What causes the most slippage? Fast-moving, high-volatility, or illiquid conditions, including but not limited to economic releases, market open and close, and gaps between sessions.