The phrase "to invest one's own money" means to use personal funds to purchase assets or make an initial financial contribution with the expectation that it will generate a return, either through capital appreciation or by receiving regular income from the invested asset. In other words, when someone says they are going to invest their own money, what they mean is that they are putting their hard-earned cash into something in hopes of making more money off of it later on. This could be done through buying stocks or bonds, starting a business, purchasing real estate, or any other number of ways in which an individual can use their own funds to generate additional wealth.