Introduction

Startups don’t win by being protected - they win by moving fast. Momentum is what gives them the chance to build a real moat later.

What’s the problem it solves?

Many founders and investors misunderstand what matters most in early-stage startups. They think a company must already have a “moat” - a lasting advantage that protects it from competitors. But at the start, no such thing exists. The real goal is to move fast, grow quickly, and reach enough scale to earn a moat later.

Quick Summary

Bryan Kim from a16z caused debate by saying “momentum is the only moat.” Critics argued that momentum isn’t real defensibility, but that misses the point. For early-stage startups, speed and traction are everything. True moats like brand trust, economies of scale, embedding, and network effects only appear after growth. Before that, all a startup can control is how fast it can attract users, revenue, or attention.

Momentum is what lets you survive long enough to build a lasting edge. Every major company - Amazon, Airbnb, Booking.com - started without defensibility. Their speed brought users, their users brought scale, and that scale later turned into real moats. The mistake investors make is judging new startups by the standards of big ones. A startup doesn’t plan its moat; it grows into it.

The simple sequence is: momentum → adoption → scale → moat. That’s the real growth path. Trying to design a moat too early distracts from what matters: gaining speed, users, and learning fast enough to stay alive.

Key Takeaways

• Momentum isn’t a moat but the path to building one.
• No early-stage startup has defensibility; only speed and attention.
• True moats (brand, network effects, embedding, scale) appear only after growth.
• Momentum turns into adoption, adoption into scale, and scale into power.
• Investors often misjudge early-stage startups by late-stage rules.

What to do

• Focus on momentum - fast growth in users, engagement, or revenue.
• Build growth loops that keep compounding attention.
• Measure retention and engagement early to find traction.
• Ignore “moat talk” until after product-market fit.
• Move fast enough that defensibility becomes possible later.

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