Your top customer is 42% of your ARR

Most founders know their biggest customer.

Few have run the scenario: what happens if they leave?

Customer concentration is one of the most common findings in a Levian report. The math comes directly from the transaction file. A typical scenario: the top customer represents 42% of monthly revenue. The top 10 account for 68%.

Neither number is alarming on its own. Plenty of growth-stage companies look like this.

But the number alone is not the finding.

The finding is what that percentage means when you layer it against retention.

If gross revenue retention is running at 75%, roughly a quarter of last month's revenue is not repeating. The business is replacing that base every month. It can still grow. But the scenario where the top customer leaves does not land in a stable foundation. It lands in a business already working to replace a quarter of its revenue, now without the account that drives 42% of the total.

The departure of that customer would not create a gap. It would break the business at its current trajectory.

Levian does not just show you the concentration number. It reads it against your actual retention data and annotates what it means for the specific business you are running.

Concentration is not always a red flag. A large customer in a business with durable net revenue retention and expanding cohorts is a different conversation than the same customer in a business where most customers finish and leave.

The report tells you which one you are.

Before the investor asks.