The "S&P 500" appears to be in the "new paradigm" phase of euphoria with nothing stopping the very strong bulls in their relentless push higher and higher. With some luck the open gap gets filled with a brief sharp drop and the market continues to rally higher from there. I simply can't recommend to go long at e.g. currently 2747 points with the market being this stretched to the upside and the US government shutdown event looming in January 2018.
Long entry: 2715 (price area of the unfilled gap)
Stop loss: 2675
1. Target 2800 (near R3)
2. Target: 2850 (near R4)
Risk to SL at 2675: 40 points
Reward (1. Target): 85 points
Reward (2. Target): 135 points