The 16700 which was a resistance level during August should be a strong support to Nifty now. This line also corresponds to the 0.5 Fibonacci retracement in Nifty. Once Nifty reaches 17700 to 17600 I'll close my short positions in Nifty as a quick short covering rally might occur. If nifty breaks and closes below 17600, then we can short again for 0.618 retracement which is at around 17200 levels.