Nvidia was rising early Wednesday amid a broader chip-stocks rally. While the move pushes it above the psychologically significantly $200 level, it was only a small boost compared with Advanced Micro Devices ’ 17% gain on the back of AMD’s strong earnings Tuesday afternoon. Heading into Wednesday, Nvidia has been the single worst performer in the PHLX Semiconductor Sector index, which tracks 30 U.S. chip companies, over both the past month and the past three months through to Tuesday’s close, according to Dow Jones Market Data.