Markets falling on huge volume, Nifty near first target 16900

Notice the chart, markets are falling with gap down and huge volumes for last few day. Today's sell-off in the last one hour (currently its 3:10) is also with huge volume. This is not a good sign. Though short term indicators are over-stretched, overall sentiment seems quite bearish. Sell on rallies or wait for market to find a bottom and consolidate, if you are looking for longs.