A staggering rise in shares of chipmaker Nvidia helped the SPDR S&P 500 ETF Trust become the first exchange traded fund to top $500 billion in assets, market participants said. A sizeable chunk of those gains came from the surge in Nvidia, whose heavy weighting in the S&P 500 gives it an outsized influence on the index’s moves. “This is a result of Nvidia climbing to new highs rather than of fresh demand for the ETF,” said Todd Rosenbluth, chief ETF strategist at VettaFi.