Yesterday the Sensex posted a new high on the back of some short covering albiet lower volumes. Weakness in the global markets coupled with nearing of the F&O expiry could see the index exhibit wild swings in intra-day deals.According to Vijay Bhambwani, CEO & Investment Consultant of BSPL India, the traded volumes need to perk up if the uptrend is to prove sustainable in the coming days. Unless retail buying emerges at higher levels, the uptrend will stand a fair chance of petering out after the February derivatives series expires.