Citigroup strategists, led by Chris Montagu, warn of a significant risk of sell-off in US technology stocks due to extended bullish positioning despite recent market declines. With approximately $22.5 billion in long positions on Nasdaq 100 Index futures, any negative economic data could trigger substantial pressure on these positions, potentially amplifying downward market movements. This vulnerability comes as tech stocks face scrutiny over high valuations amid a slowing US economy, with the Nasdaq 100 still about 10% below its July peak. Investors are now closely watching upcoming economic data, particularly inflation figures, for insights into potential Federal Reserve interest rate cuts.