Turn-of-Month Bond Seasonality and the Risk of Abandoning Noisy Edges
Summary
The article reviews a strong year for diversified systematic trading and focuses on a bond strategy that buys shortly before month-end, sells at month-end, and re-enters after a few days. The author describes institutional rebalancing and portfolio presentation as possible contributors to the recurring seasonal flow. The strategy had historically shown roughly Sharpe 1 behavior and was invested about half the time, but a weak period led the author to stop trading it. In the following year, it would have produced a strong return after costs.
The central lesson is that a short losing run does not establish that a modest Sharpe edge has vanished. Historical variation can include extended drawdowns, and plausible stories about market change or crowding may simply rationalize reacting to noise. Because the proposed flow driver is diffuse and hard to observe, the article says real-time diagnosis is limited. It recommends setting expectations for performance variation and drawdown duration in advance, defining evidence that would invalidate the strategy, and reducing exposure if needed rather than abandoning it impulsively. The discussion is an individual retrospective, and the seasonal explanation is suggestive rather than a confirmed causal mechanism.
Key ideas
- Turn-of-month bond buying and selling is presented as a simple seasonal strategy linked to possible institutional flows.
- A Sharpe near 1 can include long periods of underperformance without proving an edge has disappeared.
- Plausible explanations for a drawdown can be narratives imposed on random variation.
- When a strategy lacks an observable causal mechanism, a short sample offers weak evidence about whether it has stopped working.
- Set drawdown expectations and criteria for abandoning a strategy before trading it, and consider reducing position size during uncertainty.
Tags
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.