Traders stand outside of the New York Stock Exchange on the first day of opening since Hurricane Sandy October 31, 2012 in New York City. - 

Trading in U.S. stocks resumed today after two days off. A two-day shutdown on Wall Street is almost unheard of -- 9/11 shut down trading for four days. The last time a storm shut down trading for this long since 1888. Not surprisingly, many folks are treating this week as a learning experience.

Mellody Hobson, president of Ariel Investments in Chicago, shares her thoughts on what to expect today. "I think there's a lot of pent-up demand," she says.

Hobson believes that shutting down the market while Superstorm Sandy moved inland was beneficial.

"There are a lot of great learnings that come out of a period like this. It allows us to test a lot of our disaster recovery systems. It allows us to test a lot of the things that we just don't know how they work. So at the end of the day, this probably actually benefits the market long term," says Hobson.

Hobson says that a couple of days with no market trading really doesn't mean anything to the typical investor or their 401(K) plan or their IRA.

Gus Faucher, senior economist with the PNC Financial Services Group in Pittsburgh, also discusses in-person versus electronic trading.

Follow Jeff Horwich at @jeffhorwich