Perhaps a coworker purposefully tries to make your life miserable because they resent your success. Maybe you get passed over for a promotion and a raise because you weren’t vocal enough about your abilities, and mistakenly thought you worked in a meritocracy. Or maybe you have a new boss who decides to clean house and hire her own people. Whatever the case may be, you will eventually tire.
Investing in rental properties: Another form of real estate investment, rental investments (i.e. becoming a landlord) could steer you down the passive income path of steady monthly rent checks that you can use to pay off a mortgage loan on the rental property. After the mortgage is paid off, those monthly checks go right into your bank account -- potentially for years to come. 
Venture Debt ($12,240/year): The first venture debt fund has returned almost all my initial capital so I decided to invest $200,000 in the second fund. I took a risk investing $150,000 in my friend’s first fund, so I’m hoping there’s less risk in the second fund given he has four more years of experience on top of his 12+ years experience running a venture debt portfolio for another company.
Thanks for asking. https://passiveincomemd.com/what-is-passive-income/ gives a good summary of the definition I use. But in brief, it’s income that isn’t proportional to the time you physically put into acquiring it. It doesn’t mean it’s not without work or effort. It’s just that most of the work is done up front and it continues to pay off long after that initial effort. Real estate fits into that box. There’s definitely a spectrum but compared to what we do as doctors, where our compensation is directly linked to our time, most of these things are quite passive.
You are also free to choose a fund that is based on any index that you want. For example, there are index funds set up for just about every market sector there is — energy, precious metals, banking, emerging markets — you name it. All you have to do is decide that you want to participate, then contribute money and sit back and relax. Your stock portfolio will then be on automatic pilot.
Managerial accounting defines residual income in a corporate setting as the amount of leftover operating profit after all costs of capital used to generate the revenues have been paid. It is also considered the company's net operating income or the amount of profit that exceed its required rate of return. Residual income is normally used to assess the performance of a capital investment, team, department or business unit.
×