Valued at $43.4 billion by market cap, Monolithic Power (MPWR) is a semiconductor stock that has delivered market-thumping returns for long-term shareholders. The company went public in November 2004 and has since returned 9,200% to investors. If we adjust for dividend reinvestments, cumulative returns are closer to 10,350%. Monolithic Power designs, develops, and sells semiconductor-based power electronic solutions for several markets, such as computing and storage, automotive, industrial, and communications. It provides direct current to integrated circuits (ICs) that control voltages in var…