The levels of 39015/11515 are very strong supports for the markets and only with a close below these levels, we could see a sustained downtrend.
On the other hand, the markets will need a huge push to close above 39580/11681.
Day traders in the Nifty are better off playing the 11515-11681 range for now; only with a close outside this range will we see a major move in the direction of the close.
If you're a conservative trader, stick to stock-specific opportunities - rather than take a directional call on the Indices.
Aggressive traders can hold on to their existing shorts, but add fresh shorts only with a close below these levels.