Jeremy Siegel, Wharton School professor of finance, joins 'Closing Bell' to discuss Janet Yellen as Treasury Secretary, the Dow hitting 30,000 points and where he thinks the market can head from here. The stimulus has provided the market with liquidity that we have not seen for 75 years, says Siegel. I think the rotation will continue. I don't think we'll see a sell-off in technology. But a reopening is going to happen in 2021. I think the whole market will go up, Siegel adds.