Twitter (TWTR) stock opens at 73 percent above its IPO price, continues to climb

Puts Twitter's value at more than $31 billion

Twitter's stock opened at $45.10, or 73 percent above its IPO price, valuing Twitter at more than $31 billion. The stock is now trading even higher, at $47.85.

Twitter's trading debut is the most highly anticipated since Facebook's last year. Twitter is trading under the ticker symbol "TWTR."

Twitter priced the initial public offering of stock at $26 per share, valuing the company at more than $18 billion based on its outstanding stock, options and restricted stock that'll be available after the IPO. The pricing means the short messaging service will raise $1.8 billion in the offering, before expenses.

The high price comes despite the fact that Twitter has never turned a profit in seven years of existence. Revenue has been growing, but the company is also investing heavily in more data centers and hiring more employees.

Here's a running account of Twitter's first few hours of trading, presented in reverse chronological order. All times are EST.

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- 11:05 a.m.: RT @KenSweet: Twitter took a long time to open due to the deal size. Goldman also likes to take its time.

Goldman Sachs, Morgan Stanley and JPMorgan Chase are the three investment banks in charge of Twitter's IPO.

After debuting at $45.10, the stock is now trading at $47.85, or 84 percent above the IPO price.
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- 10:55 a.m.: AP's @BarbaraOrtutay notes that the $31 billion value puts Twitter in the ballpark of Yum Brands and Deere & Co.

It's also slightly below State Street Corp.
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- 10:53 a.m.: The opening price values Twitter at $31.3 billion.

To calculate its value, the AP is using 694.8 million shares that Twitter is expected to have outstanding after the IPO, counting restricted shares and stock options it plans to issue to employees. At the $26 IPO price, the value was more than $18 billion.
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- 10:51 a.m.: Twitter stock opens at $45.10, 73 percent above IPO price
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- 10:50 a.m.: Range is now $45 to $45.25, or up to 74 percent above IPO price. Very close to debut.

RT @KenSweet: They're closing the book.
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- 10:45 a.m. AP's @KenSweet says current bid is $45.25. The debut is near in #TwitterIPO.
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- 10:40 a.m.: Patrick Stewart tweets on #Ring of opening bell as Twitter trade debut imminent.

RT @SirPatStew: Honored to join @ev @jack @biz @dickc & the @Twitter team at their historic IPO this morning. #Ring! pic.twitter.com/XaJpYW2kIh
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- 10:35 a.m.: It's getting close to Twitter's stock debut. First indication for opening price is even narrower: $45.50-$46.50.
The high end would be 79 percent above its IPO price.
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- 10:30 a.m.: AP's @KenSweet now says opening price narrowed: $45-$47.
He reports: "This is a good sign. Could mean we're finding the right price. Progress."
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- 10:20 a.m.: AP's @KenSweet says opening price is expected even higher: $43-$47.
The range for first indication means Twitter could start trading at up to 81 percent above its IPO price.
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- 10:15 a.m.: RT @KenSweet: I've heard some traders mention that this may not open until 1030, maybe 11. But things are changing rapidly.
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- 10:10 a.m.: AP market reporter @KenSweet explains the role @Barclays has in #TwitterIPO.

Trading for Twitter's stock is under the supervision of Barclays Capital. Twitter hired the bank to be its "designated market maker." A DMM supervises the trading of a company's stock. He or she is an experienced trader in charge of ensuring that buying and selling go smoothly. If trading becomes volatile, the DMM can step in and buy shares using his or her firm's own money.

DMMs are especially important the day a company goes public, because the DMM coordinates between Twitter, the company's investment banks and NYSE's floor traders to get a stock trading. If technical problems arise, the NYSE uses DMMs to bypass electronic trading systems, allowing humans to trade a company's stock. That is not possible on all-electronic stock exchanges such as the Nasdaq, which had technical problems during Facebook's IPO last year.

Barclays' role as Twitter's DMM does not mean it is in charge of the entire IPO process. That role falls to Twitter's investment banks: Goldman Sachs, Morgan Stanley and JPMorgan Chase.