Strategy to buy ETFs index

Go for a simple, stress-free and long term approach. For this purpose, Warren Buffet and not only him suggests to put:

• 10% of the cash in short-term government bonds,
• 90% in a very low-cost S&P 500 index fund.

JL Collins suggests to go even to 100% with your investment in stocks while you are in your productive years. Later you will shift part of your investment in bonds.