Analyzing the execution of large stock orders requires a nuanced approach that goes beyond simple size comparisons. When evaluating a 3,000-share order against a 100-share order, attributing higher costs solely to the larger size fails to provide actionable insights. Effective analysis necessitates comparing like-sized orders—specifically 3,000-share orders of similar securities, liquidity, volatility, and trading conditions.
Such targeted comparisons allow for better assessment of execution performance by controlling for the inherent difficulty in filling larger orders. For example, if a manager’s 100-share orders for liquid large-cap stocks average an effective spread of 1.5 basis points, while 2,000-share orders reflect a higher average of 7 basis points, these figures alone do not indicate that internalization is to blame.
Instead, understanding the performance of comparable 2,000-share orders routed externally under similar circumstances is critical. If these external orders incur execution costs of around 6.8 basis points, it suggests that factors related to order size and difficulty account for the difference. Conversely, if such orders result in costs of approximately 3.5 basis points, it warrants a deeper exploration of the routing models used for large orders within that liquidity segment.
Why this story matters
- It highlights the importance of accurate benchmarking for trading performance in large equity orders.
Key takeaway
- Analyzing execution should focus on comparable order attributes to identify true performance issues.
Opposing viewpoint
- Some may argue that larger orders inherently incur higher costs regardless of other factors, challenging the need for detailed comparative analysis.
