Stock market today: Dow futures fall, S&P 500 and Nasdaq futures climb ahead of Fed decision, Big Tech earnings

US stock futures were mixed ahead of a critical day for markets, with a Fed decision and earnings results from Microsoft (MSFT) and Alphabet (GOOG) on deck.Futures on the Dow Jones Industrial Average (YM=F) declined by 0.3%, while those on the S&P 500 (ES=F) traded above the flat line, and contracts for the tech-heavy Nasdaq-100 (NQ=F) rose 0.3%.Sentiment in the tech trade has markedly improved this week, with the S&P 500 and Nasdaq posting back-to-back gains. Semiconductor stocks drove the rally on Tuesday after Broadcom's CEO negotiated for a consortium of banks to announce a $63 billion financing structure for building AI compute capacity.Attention now turns toward the Federal Reserve's interest rate decision at 2 p.m. ET, where the Fed is expected to hold rates steady despite elevated inflation readings. Fed Chairman Kevin Warsh's press conference will be closely watched for any signs of a hawkish bias. (Follow live updates from the meeting.)Earnings season continues apace as two Big Tech giants and cloud leaders — Microsoft and Alphabet — deliver updates on AI demand and their capex plans after the bell. Microsoft's report comes just after it offered buyouts to up to 60,000 employees as it tries to streamline operations amid the AI build-out.Rounding out the earnings picture are Ford (F), GE Vernova (GEV), T-Mobile US (TMUS), eBay (EBAY), Chipotle Mexican Grill (CMG), and ServiceNow (NOW).