Novo Nordisk stock has been pretty volatile lately, making it hard to judge whether now is a good opportunity to buy shares.Over the last couple of years, Danish company Novo Nordisk (NVO 2.83%) has evolved from a relatively obscure pharmaceutical business to perhaps the biggest rising star in healthcare.The company's breakthroughs with glucagon-like peptide-1 (GLP-1) agonists gave birth to a host of blockbuster medications that are used to treat diabetes and obesity. Chief among its offerings are Ozempic a ...