A Market Order is executed immediately at the best available price in the order book. However, to protect users from the risk of being filled at excessively deviated prices, each trading pair has a maximum slippage limit (Price Cap/Floor Ratio).
Specifically, a Market Order can only be executed within a certain percentage range above (for buy orders) or below (for sell orders) the mark price.
If the remaining order volume falls outside this allowable range, the system will stop execution, and the order may only be partially filled. This mechanism helps prevent prices from being pushed too far during periods of high volatility or low liquidity.
Example
With a ±15% limit and a mark price of 10,000 VNDC:
A Market Buy Order can only be executed up to the slippage price of 11,500 VNDC.
A Market Sell Order can only be executed down to the slippage price of 8,500 VNDC.
If the prices in the order book exceed this boundary (e.g., 11,600 for a buy or 8,400 for a sell), the system will stop, and the unfilled portion of the order will not be executed.
Notes
Each trading pair has its own slippage limit. Users can view this information in the “Trade Info” section on the app and the “Trading Rules” section on ONUS Pro (web version).
TP/SL orders are Stop Market Orders and therefore subject to the slippage limit. In some cases, TP/SL orders may only be partially filled—or not filled at all—if the market price goes beyond the allowable slippage range.
For large-volume orders or illiquid markets, users are advised to consider splitting orders into smaller sizes or using Limit Orders to optimize their investment strategy.