The most liquid of the private investments are investing in equity or credit hedge funds, real estate funds, and private company funds. There will usually be 6 month – 3 year lockup periods. The least liquid of the private investments are when you invest directly into private companies yourself. You might not be able to get your money out for 5-10 years, depending on the success of the company and upcoming liquidity events.
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.
Ebooks, which can be published through sites like Amazon Kindle Direct Publishing, are an increasingly popular option. Because these books are self-published, the process is quicker, allowing you to build residual income faster than the traditional publishing route. Whether it’s a romance novel or a how-to book on fly fishing, you can create a book and have it available for purchase in a matter of weeks.

​Self Publishing is mainstream today. When you purchase an eBook off of Amazon there’s a pretty good chance you’re buying a self-published book. Self-publishing is also ridiculously easy. I tried this a few years ago and couldn’t believe how simple the process was. To self-publish a book you’ll first need to write and edit it, create a cover, and then upload to a program such as Amazon’s Kindle Direct Publishing. Don’t expect instant success though. There will need to be a lot of upfront marketing before you can turn this into a passive income stream.

If you’ve got a book you’re itching to write, you can still go with the traditional publishing route. (We published our first book using a traditional publisher.) Whether your book is fiction or non-fiction, a publisher can help get your book into print and onto shelves in both online and traditional book stores. This is still a good route, although it may take more work and be more expensive than some other options.

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.