AdvisorShares CEO Noah Hamann (Noah Hamman) believes that the surge that currently sweeps Wall Street is a classic asset bubble that will burst sometime in 2020.

Mr Harman says bubbles are forming across asset classes and will continue for some time.

At present, almost all kinds of assets are in the rising mode. Investors seem to be worried about missing out on the market rally and begin to misestimate asset risk completely. Usually, this ends up bad for investors.

Take gold as an example. Gold prices fluctuated largely in a range from early September to early December as investors sold gold to support more liquid stocks. But despite the melt up of the main stock indexes before the end of the year, gold triggered bidding in December, surging to a seven-week high.

This momentum has spread to VanEck Vectors Goldminder ETF. Renaissance Macro Research points out that the index has risen 5 per cent in the past two trading days. Meanwhile, silver prices rose about 6 per cent last month, while copper rose 7 per cent this month. Strategists at Renaissance Macro Research believe that gold and silver are expected to challenge highs since September in early 2020.

Of course, the bubble that seems to be inflating is also evident in stock prices. Chip unitAMDIts share price soared 20% last month.

AppleAndTeslaIt could also be included in the bubble camp. Apple Inc's share price rose about 10 per cent in December, bringing it to 83 per cent year-to-date. Tesla, Inc. 's shares hovered near record highs after surging 32 per cent this month. At a market capitalization of $77 billion, Tesla, Inc. 's market capitalization is almost twice that of Ford, although its profit prospects are still questionable.

Mr Harman believes the Fed's actions are "driving up prices everywhere". He cautioned that if the Fed hinted at a change in interest rate policy by mid-2020, the bubble could burst.

"this could be a huge bubble and we could see the market plummet by 50% or 60% so quickly that investors don't even have time to react," Harman said. "

Until then, Harman advises staying bullish.