when the cashflow is negative

so that you need to feed money into the investment from other source, but the properties are in high-demanding areas with high appreciation prospect, then it is high risk.

If your overall rental cashflow is even, I guess it is modest risk. Worst come to worst, you go on street to beg for your food, but your investment still can sustain itself.

If cashflow from the rental is positive, then even you lose your non-rental income, you still can live on the rental. Then it is low risk. Unfortunately, these kinds of properties have low appreciation prospect.

Overall, if you are young, and non-rental income is quite secured, you may go for high-appreciation way. If you are closing to retirement, or with less secured non-rent income, it is better to choose better cashflow properties.

One more thing to conside is that, like sweetppt showed before, high cashflow properties are also in dangerous areas, one more question you need to ask yourself, can you carry a gun to collect rent? And second question is, is it worth your life to invest there?