Technically Speaking
Demand at 320 has held going back to February of 2015.
If that level fails to hold, the next level of support is at 260, 18% to the downside.
Risk
What is the probability of a permanent loss of capital?
How much of my capital am I going to put at risk? 1%, 3%? You have to make this decision. Remember, deep drawdowns are hard to come out of, the number one rule in my book is to limit the downside.
Quote
"Great spirits have always encountered violent opposition from mediocre minds"- Albert Einstein