With the same variety and the same spread, why do some people place orders at very low costs, while others suffer from slippage? The answer often lies in the relationship between order size and market depth. Small orders are completed within the existing quotation, and the cost is stable; large orders will eat up multiple levels of quotations, and the actual transaction price deviates from the current price. This article talks about how quote depth affects your true costs.

What is quote depth

Quotation depth refers to the amount of orders that can be accepted at the current buying and selling prices. Thick depth means that there are a large number of pending orders near the current price, and a large order can be filled without significantly pushing the price; thin depth means that a small amount of orders can cause the price to jump significantly. The spread is only on the surface, and the depth determines what price you can actually trade at. You don't need professional tools to judge the depth and thickness. You can get a rough feeling by observing whether your slightly larger order can be filled near the current price.

The cost difference between small orders and large orders

Small orders (such as a fraction of a standard lot) can usually be completed between the current buying and selling prices, and the cost is the spread; but after the order volume exceeds a certain depth, the remaining parts must be completed at the next worse price, which is the market impact cost. The larger the order, the more depth levels are consumed, and the further the average transaction price deviates from the current quotation. This is why the same strategy is often less effective when executed with large positions than with small positions.

Cost difference between market order and limit order

A market order seeks immediate execution, at the expense of possible slippage; a limit order specifies a price, and may or may not be executed. When liquidity is good, the slippage of market orders is usually very small; when liquidity is poor or the market is violent, the slippage of market orders will be significantly magnified. Understand this difference, and you can make an active choice between "must close the transaction" and "control the transaction price" instead of passively accepting it.

Cost control for large transactions

If your order volume is large, placing orders at direct market prices will incur higher impact costs. A common response method is to split the order: split the large order into multiple small orders, spread them over a period of time, and gradually complete the transactions to reduce the impact on a single price. This is no secret, but the platform needs to support flexible order management and historical transaction records in order to be executed clearly. The cost of splitting an order is time cost - you may miss a period of the market, so whether to split the order or not depends on the balance between the size of the order and the urgency of the market.

Depth also changes over time

The quotation depth is not constant: it is thin during the Asian period, thick during the European and American overlapping periods, and may be temporarily unbalanced at the moment of data release. The cost of executing the same order at different times may vary greatly. Incorporating changes in depth into trading session selection is just as important as selecting sessions with tight spreads.

Take WMAX as an example: understand depth and execution clearly

Putting depth and execution costs on the platform, WMAX provides real-time buying and selling quotations and order execution feedback, allowing traders to observe the actual transaction status of their orders; historical transaction records facilitate review of slippage and impact costs of each order; flexible order types (market price, limit price, stop loss, etc.) support traders in choosing appropriate execution methods in different depth environments. It should be noted that depth and slippage are affected by the overall liquidity of the market. The platform can only present the execution results and cannot eliminate the fluctuations of the market itself. Whether WMAX is suitable for you depends on your specific requirements for order execution quality and cost control.

write at the end

The spread is just the starting point of the cost, the depth and order size determine how much you actually pay. Look at the quotation for small orders, the depth for large orders, the slippage for market orders, the split orders for large orders, and the liquidity during the time period - the sum of these layers is the true cost of a transaction. Regardless of whether you choose WMAX or other platforms, it is recommended to evaluate the relationship between the order size and the current depth before placing an order, and always control the risk within an acceptable range. Leveraged trading carries high risks. Please fully understand the relevant rules before entering the market and make prudent decisions.