Cheatsheet for ETF Selection

1. Fund's Longevity
How many years have the fund been effective. Longer history suggests stability and track record to see the results. That said, past data does not imply future performance. 

2. Fund Size
At least USD 100 million AUM (Assets under Management). 
Larger AUM is better. 

3. Expense Ratio
The % of funds that the AM (Asset Manager can withdraw each year to pay for the fund's operating expenses.
Lower, better. Vanguard is known for having low expense ratios.

4. Tracking Error
The deviation from the underlying index. 
Less is better.