NEW YORK (TheStreet) --Shares of ZTO Express (ZTO) began trading on the New York Stock Exchange Thursday morning, opening at $18.40 per share. ZTO Express is a Chinese delivery company and is the largest U.S. IPO of the year.

"This was a very tough one to price because it was global demand. It is a very well-known brand name in China and it was the biggest IPO of the year, $1.3 to $1.4 billion offering," CNBC's Bob Pisani reported from the floor of the NYSE during the first trade of the stock.

He noted the obvious demand for the stock as investors want more access to the Chinese consumer and the Chinese e-commerce market.

"It's been very difficult to access that if you're an American investor. On the other hand, you have to figure out what kind of demand there might be in China, so they priced it aggressively, that's the bottom line," he noted during Thursday morning's "Squawk on the Street."

The "bottom line" Pisani explained is that the initial price of $18.40 places the stock at the top-end of the range of pricing.

"Overall the important thing is we have another company, more access to the Chinese consumer, more access to the e-commerce market and that's what people were looking for," he added.

Shares of ZTO Express were lower in mid-morning trading on Thursday.