Two opposing forces govern stock prices: momentum (things in motion tend to stay in motion) and mean reversion (things that have moved too far tend to snap back). The tension between them is where most traders get destroyed — and where a systematic approach shines.

The Momentum Effect

Jegadeesh & Titman (1993) demonstrated that stocks with strong returns over 3–12 months tend to continue outperforming. This "momentum effect" has been replicated across markets, asset classes, and time periods. Carhart (1997) later showed it was significant enough to become the fourth factor in asset pricing models.

Why does momentum persist? Because information takes time to be fully absorbed. When a company reports strong earnings, the initial move captures the headline. But it takes weeks for analysts to update models, funds to rebalance, and the broader market to fully price in the implications.

When Momentum Fails

Momentum doesn't fail randomly — it breaks down when a stock has moved too far, too fast, relative to its normal behavior. That's where mean reversion kicks in.

DeBondt & Thaler (1985) documented that stocks with extreme 3–5 year returns tend to reverse. But mean reversion also operates on shorter timeframes: an RSI above 80 doesn't mean a stock will crash tomorrow, but it does mean the current rate of advance is unsustainable.

How We Measure It

Alpha Pulsx evaluates momentum through multiple lenses:

  • RSI (Relative Strength Index) — Measures the speed and magnitude of recent price changes. Extreme readings flag overextension.
  • MACD — Captures the relationship between fast and slow momentum. Crossovers signal momentum shifts before price confirms.
  • Bollinger Band position — Where price sits relative to its own volatility envelope. Walking the upper band is bullish momentum; a retreat to the middle band signals exhaustion.
  • Moving average distance — How far price has stretched from key moving averages. Extension creates snapback risk; proximity creates launch potential.

The Dual Signal

The real power of this pillar isn't in any single indicator — it's in the dual signal. When momentum indicators say "continue" and mean-reversion indicators say "not overextended," the dimensional agreement is strong. When they conflict, conviction decreases. When mean-reversion indicators diverge while momentum rolls over, the research signal shifts.

The Alpha Pulsx edge: Most platforms show you an RSI and call it momentum analysis. We score the interaction between continuation and reversal forces, producing a single momentum score that accounts for both — and feeds it into the six-pillar confluence engine.