Cash on the sidelines is at record levels. In my opinion it is going to remain that way. The baby boomers are scared to death their life savings, and their retirement, are going to go down the drain, they will stay out of the market.
I've marked some retrace values on the SPX chart below. In addition I've marked the absolute decline off the SPX high (left side - yellow) which I think will be 30% to 40% before the decline is over. On the right in cyan, I've marked percentage declines from last nights close. An additional 20% decline from HERE is not out of the question.