Quote from Cache Landing:
I'm not coach, but I'm bored at the moment so I thought I would post my opinions for public scrutiny.
It has been my experience (as I heavily trade both individual stocks and indices) that an index such as SPX does not follow support/resistance like an individual stock does. This is probably due to the fact that one sector can overpower another. It is true that stocks can make sympathetic moves, but this is more common in indices. For example, the financial sector has a lot of influence and can pull or push the market more than another sector.
This makes forecasting an index much more difficult. This is why I would generally agree with Donna. When trading an index, one must have a feel for that index, and probabilities are key. Establishing entry and exit points on an index based on s/r is very hard. IMO overbought/oversold indicators are best for indices, but even still are more accurate for individual stocks.