The McClellan Summation Index is a market breadth indicator that is derived from the number of advancing and declining stocks in a given market. The concept of breadth is easy to understand; healthy markets have broad participation during rallies.
The S&P 500 could easily reach the 1513-1517 range; even 1528-1532ish is doable. The concern is the odds of a reversal would most likely increase, rather than decrease, on such a move. If conditions improve, we are happy to adjust with them.