Mohamed El-Erian: Rising treasury yields are flashing a warning sign

The 10-year U.S. Treasury yield remained higher than the 1.1% mark on Monday morning, after President-elect Joe Biden on Friday promised further economic stimulus that would be “in the trillions of dollars.” Mohamed El-Erian, economic advisor at Allianz and Gramercy and president at Queens College, Cambridge, joined "Squawk Box" on Monday to discuss why he thinks this rise is a sign investors must pay attention.