Shares of MP Materials declined after the of rare earth metals company said it had commenced a $500 million underwritten public offering of its common stock. The stock was off by 5.8% at $55.15 in post-market trading Wednesday. Shares, which reached an all-time high of $62.87 on Tuesday, finished the market session up less than 1% at $58.55

US-based rare earth materials miner MP Materials Corp. (MP) saw its stock soar 20% Tuesday after announcing a deal with Apple (AAPL). Apple on Tuesday said that it had committed to a $500 million multiyear deal with MP Materials to buy its rare earth magnets for the tech giant's products.