Rosenberg warns as bitcoin fizzles

Long-time market bear David Rosenberg has warned investors that the US stock market and bitcoin are massive bubbles, while the cryptocurrency plunged 16 percent yesterday after reaching a record high of US$34,000 on Sunday.

"Based on our [stock market] valuation work, we are anywhere from 20 percent to 30 percent overvalued based on a whole bunch of different metrics," the Rosenberg Research president told CNBC's Trading Nation.

Rosenberg said he is also avoiding bitcoin, which jumped as much as 305 percent in 2020 for its best annual performance since 2017.

"The parabolic move in bitcoin in such a short time period, I would say for any security, is highly abnormal," said Rosenberg.

Rosenberg served as Merrill Lynch's top North American economist from 2002 to 2009.