- Financial investment. Putting money in a system that promises to grow it for you or at least preserve it for future use (as is the case of putting it a secured case under your bed).
- Growing your human capital. This is giving up immediate earning opportunities, more pleasant use of your money and comfort to increase your education, your ability to create more valuable things.
- Entrepreneurship. I like to consider this as the ultimate investment. It is putting your money, time, knowledge and efforts into what you believe will grow big someday and more than compensate for the initial trouble.