Twitter's public debut is the most highly anticipated IPO since Facebook's in May 2012.
But Twitter has valued itself at just a fraction of Facebook and has sought to cool expectations. The company is likely hoping its stock will avoid the fate Facebook's shares, which didn't surpass their IPO price until more than a year after their offering.
Twitter also has tried to avoid the trouble that plagued Facebook's IPO, which was marred by technical glitches on the Nasdaq Stock Exchange. As a result, the Securities and Exchange Commission fined Nasdaq $10 million, the largest ever levied against an exchange. Those problems likely led Twitter to the New York Stock Exchange.
Earlier on Wednesday, Barclays Capital said Twitter had hired it to be its "designated market maker," a critical role when a stock starts trading. A DMM is an experienced trader who supervises the trading of a company's stock on the NYSE. 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.
Twitter lets users send short messages, or "tweets," in 140-character bursts and has attracted world leaders, religious icons and celebrities, along with CEOs. It now has more than 230 million users, more than three-quarters of them outside the US.