Stocks ended mixed after crude slumped to three-week lows as hopes of an OPEC deal faded. The Dow ended with gains, though, thanks to an earnings-driven increase in Boeing (BA) - Get Report shares. Comcast (CMCSA) - Get Report posted a strong earnings report. The cable company added video customers over its recent quarter, rebounding from a loss a year earlier, while NBCUniversal reported a massive jump in revenue tied to Rio Olympics coverage. Garmin (GRMN) - Get Report rose as quarterly strength in its wearables division helped to offset weakness in sales of its car GPS devices. Overall revenue rose just over 6%. Verizon's (VZ) - Get Report multibillion-dollar deal to acquire Yahoo! (YHOO) is still going forward, according to a Verizon exec. The acquisition was called into question after a massive security breach that affected 500 million accounts.