By Bret Kenwell Nvidia stock has rallied more than 50% from its October low. As it runs into the 200-day moving average, here’s how to trade it now. Nvidia (NVDA) – Get Free Report stock slumped earlier this year, but it has found its footing and enjoyed a monstrous rally. The graphics-chip specialist’s shares bottomed on Oct. 13. Since then, the stock has posted a gain in seven of the past eight weeks and is up more than 57% during that stretch. That move outpaces even Advanced Micro Devices (AMD) – Get Free Report when it was trading at its highs from a few weeks ago. While AMD stock has sin…