Every founder says their startup is defensible. Few actually are at the early stage. Here's how to assess what's real.

The five types of moats

Network effects: The product gets better as more people use it. Marketplaces, social platforms, and communication tools have this. Ask: "Does adding one more user make the product better for existing users?" If yes, there's a potential network effect. If no, it's just a user base.

Switching costs: It's painful for customers to leave. Enterprise software with deep integrations, platforms where users store years of data, or tools embedded in daily workflows. The test: "If a competitor offered the same thing for free, would customers switch?" If switching is hard regardless of price, the moat is real.

Data advantages: The startup has access to data that competitors can't easily replicate. This only counts if the data improves the product in a meaningful way and is genuinely difficult to acquire.

Brand and trust: In regulated industries or high-stakes decisions, brand matters. A fintech startup with regulatory approval has a moat that takes competitors years to replicate.

Cost advantages: The startup can deliver the same value at lower cost due to technology, scale, or operational efficiency. Rare at early stage but possible with novel technical approaches.

Most early-stage moats are future moats

At pre-seed and seed, most startups don't have a real moat yet. And that's normal. What matters is whether the plan creates one over time.

A marketplace with 50 users doesn't have network effects. But if the unit economics work and the growth plan is sound, network effects will emerge at scale. Your job is to evaluate whether the path to a moat is credible, not whether the moat exists today.

Red flags

"Our moat is our technology" - without patents or genuine technical complexity, code can be replicated
"We're first to market" - first-mover advantage is overstated; execution matters more
"Our team is our moat" - teams can be hired away; this isn't defensible
"We have partnerships" - unless exclusive and contractually locked, partnerships aren't moats

The honest assessment

Ask the founder: "If Google decided to build this tomorrow, what would stop them?"

The answer should be specific. "They can't because they don't have our data set from 5 years of X" is strong. "They wouldn't because it's too small for them" is honest but not a moat. "They can't because we're better" is delusional.

The best founders are honest about where their defensibility is weak and have a plan to strengthen it. That honesty is a better signal than any claim of invincibility.