It's showtime!   The grand finale of earnings season is here, with a lot riding on Nvidia's (NVDA) Q3 results after the bell. Expect impressive numbers due to explosive AI and data center demand, though the level of growth and guidance should be of more importance to the Nvidia story. Margins are also on watch as the company ramps up its Blackwell GPUs, as well as whether overheating issues related to the coveted processors are real or fake news. Note that options trading should lead to big price swings ...