New Delhi, Aug 25 : The Nifty is hovering near the important and crucial support zone of 19,270 levels which is also where the significant 50EMA lies, and a decisive breach below the 19,250 - 19,270 zone shall weaken the overall bias and can trigger for further slide with next major support zone visible near 18,800 - 18,900 levels with 19,000 as the psychological landmark in-between, says Vaishali Parekh, Vice President - Technical Research, Prabhudas Lilladher. At the same time, from current levels for the bias to improve, would need a decisive breach and sustain above 19,500 levels to anticipate further rise. So till then, one can maintain a cautious approach and go for only select stocks, Parekh said. An unhealthy trend in the market is the sustained rise in the prices of many small-and micro-cap stocks, says V.K. Vijayakumar, Chief Investment Strategist at Geojit Financial Services. This is partly aided by the sustained flow of funds into the small-cap segment. Valuations in the segment are approachingrisky levels. Safety is now in large-caps, he added. The market is delicately poised waiting for triggers. The transient role of sentiments was evident on Thursday when the market couldn't sustain the enthusiasm triggered by the successful Chandrayaan-3 mission and its positive impact on stocks related to the mission, he said. The message from the Fed chief Jerome Powell Friday night will be keenly watched for any clues on the future trajectory of interest rates in the US. The Fed chief is unlikely to indicate that the rate hiking cycle is coming to an end, he added. /IANS