This is a simple analysis of SPY's trend.
Clear as day, SPY's price action is best contained within a rising wedge. Rising wedges have the tendency to break down after the 3rd test of the upper trend line.
If we break to the downside of this wedge, this gives us a target of 223 which is measured by the top and the bottom of the broad end of the wedge.
I think this break down will be better confirmed if the price holds below the 50% fib retracement level at 278.