The b wave apart of the ABC correction has formed a horizontal triangle, signalling the transition to the final c wave since horizontal triangles always appear in the position prior to the final move of the pattern. Wave b appears to be nearing it's top around the 880 level, while the indicators are also showing bearish divergence. But we must not negate the possibility of a breakthrough above the downtrend line to reach 900-1000 levels.
Following the c wave, we might see a bounce at around 747, a support level formed by the low from wave iv. Failing to do so will expose lower levels and perhaps create a double correction combo.