NVIDIA (NVDA. O) 's stunning rally since the start of last year has finally come to an end, at least in the eyes of New Street Research analyst Pierre Ferragu. Ferragu downgraded NVIDIA to neutral from a buy. He believes NVIDIA's stock price has "fully captured" its valuation after rising 240% last year and 157% this year. The stock fell 0.6% on Friday. NVIDIA's gains this year are the second-largest among S & P 500 stocks, behind another AI concept, Super Micro Computer Inc. NVIDIA's market value has increased by $1.90 trillion this year, once taking the crown of the world's most valuable company. New Street has set a price target of $135 for NVIDIA after a year.