U.S. stock index futures jumped on Wednesday following two days of turbulent trading, helped by stellar results from Microsoft, while investors looked to the outcome of the Federal Reserve’s policy meeting. Microsoft Corp. gained 3.9 percent premarket after the Windows maker forecast revenue for the current quarter broadly ahead of Wall Street targets, driven in part by its Intelligent Cloud unit. Texas Instruments Inc. rose 4.6 percent after the chipmaker forecast upbeat current-quarter revenue and said it would sharpen its focus on chips used in the lucrative automotive and industrial sectors. The strong outlook from both the companies lifted tech-related stocks with Meta Platforms, Apple Inc., Google-owner Alphabet Inc., Amazon.com, Advanced Micro Devices, and Nvidia Corp. rising between 2.1 percent and 3.7 percent. The rate-sensitive tech and growth stocks have been roiled over fears of aggressive Fed action to combat inflation. Rising geopolitical tensions around Russia and Ukraine added to …