Most millionaires reach that level of wealth by investing their cash into profitable assets. Investments allow your money to work for you, and the growth becomes more pronounced once you get past the first $100,000. That milestone is the hardest part about being a millionaire. That’s because of how percentages work. If your $10,000 portfolio goes up by 10%, you only have $11,000. That’s still better than nothing, but if you generate that same return on a $500,000 portfolio, your portfolio will gain an addit ...