How 10-Basis-Point Order-Book Depth Affects Large Entries

Summary

The document explains why traders placing medium-sized orders should assess order-book liquidity across a wider band around the mid-price, rather than relying only on the best quote or a narrower depth measure. It argues that a large order can consume nearby resting liquidity and extend into the 10-basis-point range, worsening average execution price. Splitting an order may reduce immediate impact but can expose the trader to price movement during execution.

It illustrates the argument with reported depth comparisons for four semiconductor perpetual contracts over a stated week, then estimates slippage and monthly execution costs for a hypothetical position and trading cadence. These figures are venue-specific, time-bound, and presented as an illustrative comparison, not a universal execution model. Actual fills depend on order type, changing liquidity, market conditions, fees, and timing; the article also makes promotional claims about one venue that its examples alone do not independently verify.

Key ideas

• The depth available within a chosen distance of the mid-price can matter more to a large order than the best bid and ask alone.
• A thin book can increase average slippage when an order consumes multiple price levels.
• Breaking a large order into tranches may add delay and expose later fills to adverse price movement.
• The document uses venue-specific depth observations and a hypothetical cost comparison to illustrate the impact of execution quality.
• Reported depth and estimated costs can change over time and do not guarantee a particular fill outcome.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.