In economics, property_income is an umbrella term for cash cow income i.e. 钱生钱. It is a subset of passive income and nonwork income.  https://en.wikipedia.org/wiki/Property_income lists 3 common types of property income:

• RR) rent .. main risk is political, legal, physical risks
• II) interest (+dividend) .. usually periodic [1].
• PP) realized profit
• —-
• aa) realized rEstate appreciation .. is not property_income IMO. This profit is similar to buy/sell of paintings.

Company profit can become unrealized gain for a small partnership, but in stock market, profit shows up as either dividend payout (or buyback) or stock rally.

[1] 1 in 20 credible stocks have a history of random dividend that is utterly unreliable. In all other stocks, either there’s no expectation of dividends, or management has the responsibility to meet shareholder expectation of non-zero dividend every year.

— I am different from peer investors in my attitudes towards property_income
Many of my U.S. peers favor PP, like a windfall
Many of my Singapore and China peers favor aa over PP (denoted “aa > PP”)
I am different. I favor RR > II > PP

— credit risk .. affects II most, also RR
— market risk .. affects PP most, and also dividends