As passive investors, many of us including myself invest regularly on a monthly basis. Additionally, some of us are investing for long term goals that includes retirement.

However, how much can most of us afford to invest every month? The numbers may differ when it comes to different financial backgrounds. Some of us can afford to invest thousands of dollars every month.

But what about us teenagers? Some of us are still schooling, some of us are serving the nation. $100 could be the bare minimum we can scrounge up every month for investing.

But what can $100 buy? If you're looking for ETFs that track the Straits Times Index, even the cheapest would be $300++ to purchase 1 lot.

Some may turn to Regular Savings Plan or use POSB/OCBC to invest. How they work is every month, your $100 buys shares with Dollar Cost Averaging (DCA). When shares are ......