Shares of Hologic Inc. shot up 10% in premarket trading Friday, after the diagnostics products and medical imaging systems company raised its fiscal fourth-quarter revenue outlook, to put it well above analyst expectations, citing increased production and strong sales of COVID-19 tests. With more than 80% of its fourth-quarter complete, the company said it now expects revenue to rise 54% to 60% from a year ago to $1.225 billion to $1.275 billion, up from previous guidance of $925 million to $1.025 billion. The FactSet consensus was $986.5 million. Other reasons for the increased outlook include strong sales of its Panther instruments and “slightly” better-than-expected performances in its breast and skeletal business and its surgical division. The stock has rallied 18.8% over the past three months through Thursday, while the S&P 500 has gained 11.2%.Market Pulse Stories are Rapid-fire, short news bursts on stocks and markets as they move. Visit MarketWatch.com for more information on this news.