With out soon, it looks like the good days for free lunch sellers will be soon over. We will see sharper moves in VIX , so in equity prices too ( SP500 respectively). My bet is we will likely not see the VIX in the 11-12 super low range, but rather ard the 13,90-14,00 equilibrium. So my game is any time it is down to 11,00 - 11,50, just buy!
The upside is a good question. 18-21 is a Take Profit range, BUT NOT A SELL FOR SHORT any more! Why not short? If once a major problem (trend break) happens on SP500 , then the 21 won't hold either.