2. One can buy ETF on the day when market falls as one is ale to get more ETF with the same money.
3. To make it simple to unerstand ETF; one can say that these are traded like shares ; however these ETF track the underlying asset or commodity or index. One will be better off investing in these ETF as it is better than index funds or commodities.
4. Drawback of ETF is that at times it becomes illiquid and thus it is better to ross check the commodity price before sealing the deal. Due to illiqidity the spread may be large in commodity or index and ETF price.