What Is Momentum Investing?

Opening Hook

NVIDIA (NVDA) gained 239% in 2023, and momentum investors who piled in during the first quarter made fortunes riding the AI wave. While value investors were still debating whether the stock was "overvalued" at $200, momentum players were already banking profits at $400. This isn't luck—it's a systematic approach that's generated billions in returns for those who understand when trends have legs versus when they're about to snap.

What It Actually Means

Momentum investing means buying stocks that are already moving up strongly, betting they'll continue climbing. Think of it like surfing—you're not trying to predict where the next wave will form, you're jumping on waves that are already building power. The strategy assumes that assets in motion tend to stay in motion, at least in the short to medium term. Technically, momentum investors screen for stocks with strong relative strength ratios, typically looking for securities that have outperformed the broader market over the past 3-12 months. We measure this using price momentum indicators like the 12-1 month return (excluding the most recent month to avoid short-term reversals).

How It Works in Practice

Let's examine Tesla's (TSLA) momentum run from October 2019 to February 2020. In October 2019, TSLA was trading around $50 (split-adjusted) after posting its first quarterly profit. A momentum investor would have flagged this when:

By February 2020, TSLA hit $190—a 280% gain in four months. The momentum strategy worked because institutional money followed retail enthusiasm, creating a self-reinforcing cycle. Professional momentum funds like AQR's Momentum Fund or even Renaissance Technologies deploy similar logic across thousands of stocks simultaneously, capturing these trend-following behaviors that persist across global markets.

Why Smart Investors Care

Professional investors use momentum as a core factor alongside value, quality, and low volatility in their multi-factor models. Cliff Asness at AQR has shown that momentum generates alpha precisely because it exploits behavioral biases—investors under-react to good news initially, then over-react later. We see this in earnings momentum strategies where hedge funds buy stocks with accelerating earnings growth, not just high absolute earnings. The non-obvious insight: momentum works best during the middle innings of bull markets, not at the beginning or end. When volatility is moderate and trends are established, momentum strategies can compound returns while value investing struggles. This is why quantitative funds allocate 15-25% of their equity exposure to momentum factors.

Common Mistakes to Avoid

The Bottom Line

Momentum investing harnesses the mathematical reality that stock price trends persist longer than efficient market theory suggests they should. The key is distinguishing between sustainable momentum driven by fundamental improvements and unsustainable momentum driven by speculation. As markets become increasingly algorithmic, will human behavioral biases that fuel momentum strategies persist, or will they get arbitraged away?