Markets took a breather last Friday as they ended in the red after four sessions of gains. Total volumes in the derivatives segment decreased by 47% to Rs 187 bn (Rs 251 bn).The discount on Nifty Aug Futures slightly widened to 33 points from 32 in the previous session. This combined with the fact that total OI increased by 7% indicates that there was a marginal build up in fresh short positions.For the Nifty to sustain the uptrend it is important that it crosses the 3170 levels convincingly. On the downside, a close below the 3,070 levels would lead to weakness.