Ponzi Indicators
1. High rate of return
Explanation: ponzi schemes typically offer very high rates of return that are not possible. Anything that is > 50%/year APR is suspicious. Anything > 500% APR is very suspicious. Ponzis can offer lower rates as well (see Maddoff - 10% APR), but these are less common.
So basically what you're saying is nearly every single Bitcoin investment/loan/offer is a ponzi, because I don't think there are many at all that offer less than 50% a year
These indicators are just things to look out for when investing. Investments that fit multiple indicators have an increased risk of being a ponzi.