A record valuation and increasingly bullish predictions from Wall Street have made Nvidia Corp.’s earnings report on Thursday one of the most anticipated of the season. Nvidia has added almost $18 billion to its market value over the past five sessions with a steady climb that left shares trading at their highest in the company’s 19-year history. Whether the stock can extend that streak will hinge on the performance of Nvidia’s gaming and data center businesses, which account for about 80 percent of revenue.