A major merger in the world of online education: Coursera will buy Udemy for about $930 million in stock, the companies announced Wednesday. The combined firm, which will focus on upskilling workers in artificial intelligence, will be worth approximately $2.5 billion. The online learning sector has been in a period of consolidation as it responds to weakening demand in the wake of the COVID-19 pandemic. Both Coursera and Udemy have seen their shares suffer this year: Coursera's are down about 7%, while Udemy's have plunged about 35%.