Post-Trade Analysis: From Data to Actionable Intelligence

For many trading desks, post-trade analysis is a perfunctory exercise, a box-ticking requirement for compliance. This is a missed opportunity of significant proportions. A rigorous and systematic post-trade analysis process is not just about measuring costs; it is about transforming raw execution data into actionable intelligence that can be used to refine strategies, reduce costs, and ultimately, improve performance. This article will outline a framework for building a world-class post-trade analysis capability.

The Goals of Post-Trade Analysis

The primary goal of post-trade analysis is to answer a simple question: "How well did we execute our trades?" However, the answer to this question is far from simple. A comprehensive post-trade analysis should seek to achieve the following objectives:

• Measure and attribute transaction costs: The analysis should accurately measure all of the costs associated with a trade, including explicit costs (commissions, fees) and implicit costs (market impact, delay, missed opportunity). It should also attribute these costs to their root causes.
• Evaluate the performance of traders, algorithms, and brokers: The analysis should provide an objective assessment of the performance of all of the actors involved in the execution process.
• Identify opportunities for improvement: The analysis should highlight specific areas where the execution process can be improved. This might include changes to the trading strategy, the choice of algorithm, or the selection of broker.
• Provide feedback to the investment team: The analysis should provide feedback to the portfolio managers and analysts on the true cost of their investment ideas. This can help them to make more informed decisions in the future.

The Post-Trade Analysis Workflow

A robust post-trade analysis workflow consists of the following steps:

1. Data Collection and Cleansing: The first step is to collect all of the relevant data for each trade. This includes the order details (symbol, size, side), the execution details (price, time, venue), and the market data (quotes, trades). This data must then be cleansed to remove any errors or inconsistencies.

2. Benchmark Calculation: The next step is to calculate the relevant benchmarks for each trade. This will typically include the arrival price, the VWAP, and the TWAP. It is also important to calculate the Implementation Shortfall, which is the most comprehensive measure of transaction costs.

3. Cost Attribution: Once the benchmarks have been calculated, the total transaction cost can be decomposed into its various components: execution cost, delay cost, missed opportunity cost, and explicit costs. This attribution is important for understanding the root causes of the costs.

4. Performance Evaluation: The next step is to evaluate the performance of the traders, algorithms, and brokers. This can be done by comparing their performance to the relevant benchmarks and to their peers.

5. Reporting and Visualization: The final step is to present the results of the analysis in a clear and concise manner. This should include a combination of tables, charts, and written commentary. The goal is to make the results easy to understand and to highlight the key findings.

Key Metrics to Track

A comprehensive post-trade analysis should track a wide range of metrics. Here are some of the most important ones:

• Implementation Shortfall: The total cost of executing a trade, including all explicit and implicit costs.
• Slippage vs. Arrival Price: A measure of the market impact of a trade.
• Slippage vs. VWAP/TWAP: A measure of the performance of a trade relative to the market.
• Fill Rate: The percentage of an order that was actually executed.
• Reversion: A measure of how much the price of a security moves back in the opposite direction after a trade. A high reversion can indicate that a trade had a large, temporary market impact.

From Analysis to Action

The ultimate goal of post-trade analysis is to drive improvement. The insights generated from the analysis should be used to make concrete changes to the execution process. This might include:

• Refining trading strategies: The analysis might reveal that a particular trading strategy is consistently underperforming. This could lead to a decision to modify or abandon the strategy.
• Optimizing algorithm parameters: The analysis might show that an algorithm is not performing as expected. This could lead to a decision to adjust the algorithm's parameters.
• Changing broker allocations: The analysis might reveal that a particular broker is consistently providing poor executions. This could lead to a decision to reduce the amount of business done with that broker.

Conclusion

Post-trade analysis is not just a back-office function; it is a important component of a successful trading operation. By systematically measuring, analyzing, and attributing transaction costs, trading desks can gain a deep understanding of their execution quality and identify opportunities to improve their performance. In today's competitive markets, a world-class post-trade analysis capability is not a luxury; it is a necessity.