Twitter (TWTR) began trading today on the New York Stock Exchange under the ticker symbol TWTR and the shares are up more than 70 percent, valuing the company at more than $31 billion. The company raised $1.8 billion with its initial public offering (IPO). The IPO share-price of $26 means the seven-year-old short messaging, social media company will raise $1.8 billion in the offering, before expenses. If the IPO raises more than $1.92 billion, with its overallotment, TWTR would surpass Google as the second-highest IPO in U.S. history. Watch for the stock to pull back later once short-term trader start to cash out their quick gains. The stock earlier this morning traded as high as $50.09 as share before pulling back to $45.66 at 11:30 a.m. EST.