For this post, I am using the most bearish of the three options, a 5th wave put in at the low of 1010.91, marking the 1st wave down (or "a"). The end, or top of the 2nd wave (or "b") is much clearer then the 1st wave, and most likely has ended at 1129.24.
Using the most bearish option, the 1st wave down was 208.89 points, and EWT suggests the 3rd wave should be approximately 1.618 times that length, or 337.98 points, since the 2nd wave ends at 1129.24, a simple subtraction yields 791.26 as a likely spot for the 3rd wave down to wrap-up. This is the worst case scenario, and is why I chose 1010.91 for the end of the 1st wave down.
One option still on the table is that the sell-off from the top of 1219.80 is part of the larger correction, most likely the "B" wave of P2, with the "hope rally" from 666 as a complex corrective wave "A" in an over-all larger structure of 3-3-5 for P2 up. If this is really a "B" wave things are only going to get more confusing as "B" waves can morph into very complex corrections. For a simple "B" wave, or zig-zag, a-b-c, it is possible that the SPX is currently in the "c of B" wave with 1010.91 marking the "a" wave, and 1129.24 the "b" wave, using this scenario, and if the "a"wave were to equal the "c" wave in length, the SPX could bottom at 920.35. This is the best case as far as I can tell using a simple zig-zag model.
The SPX is very close now to breaking below the long-term trendline from 666, and that should start another round of sell-offs as that support is broken. Any break above the thin green trendline of resistance from the top should really alarm the bears and opens the doors for another test of 1131, and even the possibility of a test of the top for a new high.