Stock Market · Trading Systems

Momentum systems

Momentum trading is a cousin of trend following. You buy what's already gone up, betting that strength continues. Unlike pure trend following, momentum systems often use shorter timeframes and explicit ranking.

Classic momentum strategy

Universe: Nifty 100 stocks.

Setup: Calculate 6-month return for every stock.

Selection: Pick top 10 stocks by 6-month return.

Rebalance: Monthly, replacing the bottom-ranked with new top performers.

Stop: Skip the strategy when broader market is in a clear downtrend.

The momentum premium

Academic research (Jegadeesh and Titman, 1993) showed that stocks that have outperformed in the past 6-12 months tend to continue outperforming for the next 3-6 months. This 'momentum premium' has persisted for decades.

Indian momentum index (Nifty 200 Momentum 30) has outperformed Nifty 50 by 4-5% annually over long periods.

Why momentum works

• Information diffuses slowly (analysts upgrade gradually)
• Institutional buying continues over weeks (large positions can't be built in a day)
• Retail FOMO accelerates trends once visible

> Momentum is the 'follow the smart money' systematic strategy. You don't need to know why a stock is rising. You just observe that it is.

Momentum crash risk

Momentum strategies have one fatal weakness: market crashes. When the entire market falls, momentum stocks (which had risen most) fall MORE than the index. 'Momentum crashes' in 2008 and 2020 wiped out years of momentum gains in months.

Defense: regime filter that switches the strategy off during market downtrends.

Index momentum approach

For most retail investors, the easiest momentum approach is an ETF:

• Nifty 200 Momentum 30 ETF
• Held for years, rebalanced automatically
• Captures the momentum premium without daily monitoring

Active momentum

For active traders, monthly rebalancing of top-N momentum stocks (after regime filter) is a strong systematic approach with manageable workload.

Takeaway. Momentum: buy past winners, expect outperformance to continue. Indian Momentum 30 index has beaten Nifty 50 by ~4-5% annually. Biggest risk: market crashes hit momentum stocks hardest. Always include a regime filter.