The aerospace and defence firm reports £11.82 billion of revenue. The British multinational's shares jumped 4% in premarket trading. Rolls-Royce Holdings plc (LON: RR) said on Thursday that its pre-tax loss widened in 2020 amidst the COVID-19 pandemic that weighed on its revenue. The company also warned that the ongoing health emergency makes it harder to predict future performance with confidence at the moment. Rolls-Royce shares jumped roughly 4% in premarket trading on Thursday but lost almost half of the intraday gain on market open. Including the price action, the stock is now exchanging hands at £1.14 per share. In comparison, Rolls-Royce had started the year 2021 at a per-share price of £1.03. The price action should come in handy if you are interested in investing in the stock market.