SPY 180-182 - the most important support

I analysed the S&P500 ETF, because this is more important than S&P500 futures or spot. The big players are owning the ETF, not the futures contracts.
I think that the most important support for the S&P500 ETF (SPY) is define by this area between 180 and 182. If the prices will break this key support, then many stop-losses could hit the market and put more pressure on the downside, eventually reaching the target at 150-155.
The market will be extremely volatile, so the position should be well managed.