Abstracting away your concept, any number could be too high even 4%. Assuming a build up method of risk, which is a practical/theoretical way you can categoriz

Abstracting away your concept, any number could be too high even 4%. Assuming a build up method of risk, which is a practical/theoretical way you can categorize returns across asset classes, you start with the "risk free rate" which often could be the US short term borrowing rate. Currently it's pegged artificially at 0.25%. From there you add risk. So a municipal bond backing a school would earn a 2% "spread" or risk premium for a 2.25% return, and your "Uber but for XYZ" would be significantly higher. Rather than picking arbitrary cutoffs it's helpful to think about returns in terms of where they sit relative to GDP growth. From 1750 to 2010 the equity and certain real markets track GDP growth (not in any particular year but in inflation adjusted terms). Which makes sense conceptually since asset markets should be a exchange rate adjusted money supply expression of GDP growth conceptually. Why does this matter? Germany, for example, has negative rates. Rules of thumb absolutely break as you tangentially approach 0% base rates. 1 . https://www.bankrate.com/rates/interest-rates/federal-funds-rate.aspx https://www.bankrate.com/rates/interest-rates/federal-funds-... 2. https://www.bea.gov/data/gdp/gross-domestic-product https://www.bea.gov/data/gdp/gross-domestic-product