Investing.com -- Marvell Technology Inc (NASDAQ:MRVL) shook off a sharp two-day slump in postmarket trade Friday following the announcement of its upcoming inclusion in the bellwether S&P 500 index. Shares of the semiconductor company bounded 6% higher in after-hours trade as S&P Dow Jones Indices revealed the changes for its quarterly rebalance. The index addition caps a highly volatile week for Marvell, which initially went on a tear after Nvidia CEO Jensen Huang called it the next "trillion-d