Shares of Novo Nordisk ( NVO 2.48%) are falling this week, down 33% as of 3:27 p.m. ET on Friday. The drop comes as the S&P 500 lost 2.4%, and the Nasdaq-100 lost 2.2%. The Danish pharmaceutical giant's stock was hit after it released disappointing earnings showing that sales of its blockbuster GLP-1 drugs remain weaker than hoped.

U.S.-listed shares of Novo Nordisk (NVO) sank roughly 20% in premarket trading after the Danish drugmaker cut its full-year outlook and named a new CEO. Novo Nordisk, which makes blockbuster weight-loss drugs Ozempic and Wegovy,