SGI was a pretty small 3D workstation company at the bottom of the S&P500, even at it's peak. Microsoft was at least a hundred times as big as SGI. (And Nvidia was even smaller, selling GPUs for both SGI worthstations and Windows PCs at the time.) Now Nvidia is a titan at #5 in the S&P. They could certainly be taken down a notch or two as CUDA alternatives mature and people start buying cheaper AMD/Intel/FPGA(groq, etc) hardware. But they're the best at what they do, with the best people. They don't really have a doomed business model the way SGI's "take out of a second mortage for the Onyx workstation to make N64 games" business model was doomed. I don't buy Nvidia stock, personally, but I especially wouldn't bet against them long term either.
