Well, I’m a millionaire. What on earth am I spending my money on? Where am I investing it? Is it really going into, like, 400 k’s and Iras? Stock market. Hmm. Check this out. Real estate is still the most popular of all millionaire investments and spending choices. For over 200 years, approximately 90% of all global millionaires, not American global, spend their fortunes on real estate investments. This trend is expected to grow. The United States millennial millionaires own an average of three properties with a real estate portfolio worth $1.4 million.