Nifty IT index fell over 7% on Monday, hitting a near 17-month low, as stock market crashed amid trade war fears.Coforge, Mphasis, HCL Technologies, Persistent Systems, and Infosys led the decline on the IT index.The IT sector's fortunes are highly linked to the US macro environment as discretionary spending by American companies drives IT services demand.Expensive valuations, weak earnings, and policy uncertainties contributed to the decline in tech stocks globally.