 Shares in Johnson Matthey PLC LSE:JMAT plunged by almost 16 after the chemicals company issued a profit warning for the current year and also announced that chief executive Robert MacLeod is stepping down and that it plans to sell its battery materials business. The chemicals group said the trading outlook for the year to March 2022 is towards the lower end of market expectations due to supply chain shortages affecting the automotive industry and precious metals prices. 