Entry
- Choose a lookback window (classically: 12 months, also 1/3/6/12 combined)
- Compute the cumulative excess return over the window
- Long if positive, short if negative — binary or scaled by volatility (vol-targeting)
- Rebalance monthly
Exit
- Signal flip at the next rebalance date
- Vol target: shrink the position when realized vol exceeds the target
- An ATR-based trailing stop is possible as a supplement
| Name | Typ. value | Description |
|---|---|---|
| lookback_days | 252 (12M) | Window for the momentum calculation; longer = less noise, more lag |
| rebalance_interval | monthly | How often it is re-evaluated |
| vol_target_annual | 10-20% | Target volatility for position-size scaling |
Pros
- Strongest academically documented anomaly alongside value
- Robust across all asset classes
- Performs better than buy-and-hold in crises (crisis alpha)
- Easy to automate, low trade frequency
Cons
- Long drawdown phases possible in trendless markets
- Weaker performance since the 2010s (crowded factor)
- Needs several asset classes for diversification to reach full effect
Core idea
Time-series momentum is the simplest and best-documented form of trend-following: if an asset has run positive over the past 12 months, it tends to keep running positive in the next month. Not relative to other assets (that would be cross-sectional momentum), but against itself.
Why it works
Moskowitz, Ooi & Pedersen (2012) documented the effect across 58 liquid futures markets — equities, FX, bonds, commodities. The authors attribute it to initial underreaction (investors adjust to news too slowly) and delayed overreaction (momentum traders enter with a lag).
Particularly important: the managed-futures hedge fund index loads fully on the TSMOM factor. Almost the entire average performance of this multi-billion-dollar industry can be explained by it.
Practical rules
- Choose a lookback window — 12 months is standard; many funds combine 1/3/6/12M equally weighted.
- Compute the return over the window (excess return after the risk-free rate).
- Long on a positive return, short on a negative one — or binary, leveraged to a vol target.
- Rebalance monthly (weekly is also possible; transaction costs rise).
Weaknesses
- Crowded: has weakened since the 2010s — too many CTAs play it.
- Whipsaw: in sideways-volatile markets it flips constantly, and costs eat the returns.
- Long drawdowns: 2-3 years of underperformance are not uncommon.
Application to Botty
Botty trades BTC perp on Hyperliquid — single-asset, so a classic TSMOM portfolio is not possible. But: TSMOM as a regime filter works. Example: only accept long signals when BTC's 90-day return is positive. This excludes roughly 30-40% of the historically worst signals without cutting into the good ones.
Literature
- Moskowitz, Ooi, Pedersen — Time Series Momentum, JFE 2012 (original paper, freely available on AQR)
- Clenow — Following the Trend (practical implementation as a managed-futures system)
- Hurst, Ooi, Pedersen — A Century of Evidence on Trend-Following Investing (215-year backtest)