China ruled that Nvidia Corp. violated anti-monopoly laws with a high-profile 2020 deal, ratcheting up the pressure on Washington during sensitive trade negotiations.The US chipmaker was found in violation of antitrust regulations after the acquisition of networking gear maker Mellanox Technologies Ltd., the State Administration for Market Regulation said after concluding a preliminary investigation. Nvidia’s shares fell about 2% in pre-market trading, while US stock index futures pared gains.The surprise a ...