Stock market live updates: Dow jumps 350, Big Tech rebounds, still 4-week losing streak

This is CNBC's markets live blog that was updated throughout the day. 

Don't miss CNBC and Institutional Investor's Delivering Alpha conference on September 30, featuring Treasury Secretary Steven Mnuchin, Senator Elizabeth Warren, Alibaba's Joseph Tsai, Vista Equity Partners' Robert Smith, J.P. Morgan's Mary Callahan Erdoes, Inclusive Capital's Jeff Ubben and more.