Based on my research, in the long run, having money managed by a broker is more expensive given that the returns are no better (and often worse) compared to having it managed by a robo-advisor. Investing in stocks, Index funds are a good bet (diversify the risk by choosing stocks comprising some index like the S&P 500) or invest in index funds focused on a particular market like real-estate. I divide my investments into 3 parts: riskiest(smallest percentage but invested in bitcoins and such), medium (index funds, forex, real estate etc.) and safe (savings account). My two cents