The key domestic benchmarks are likely to witness a weak opening today amid a bearish trend in fellow Asian peers as concerns grew that the US Federal Reserve may start tightening monetary policy for the first time since 2008 as it gauges the strength of the world’s biggest economy. China’s Shanghai Composite fell while Hang Seng tumbled after Premier Li Keqiang signaled that money supply slowed in August, indicating a deepening gloom in the world’s second biggest economy. Japan’s Nikkei 225 fell but a weaker yen, which boosts the appeal of exporter stocks, curbed losses. Back home, the Sensex may witness profit booking after surging to record highs in recent days while caution may persist ahead of IIP and CPI data due later this week which will offer further cues over the health of Asia’s third biggest economy. The scrip of ICICI Bank may witness movement after the private sector lender approved 1:5 stock split.