As per the technical truism "what was support becomes resistance," the 1640-1645 level has become new resistance for the index. Again, as I've repeated more than once in recent past postings, given we're using hourly charts the focus is short-term. Longer-term repercussions could eventually stem from these shorter-term observations, but the point being I do not wish to overstate what we're discussing here in the short-term. Let's not get ahead of ourselves.
But as I wrote on Friday, clearly this breakdown in the triangle formation has implications for S&P 500 direction over the next several days or even weeks, i.e. it does not bode well for the market near-term.