I recently spec'd out an ETF based on the number of employees working in a given MSA with the management proceeds going to support entrepreneurship in that area

I recently spec'd out an ETF based on the number of employees working in a given MSA with the management proceeds going to support entrepreneurship in that area. Fixed costs for operating a single ETF is about $250K, which means a minimum AUM of $50M with a 0.5% fee. Most platforms won't even list an ETF with < $40M because they know its not sustainable below that level. That said, for a manager of many ETFs, the fixed costs are much lower because they can be spread across multiple funds.