Update (4:10 p.m.): Updated with Tuesday market close information and Daniel Graf hiring news.
According to The Wall Street Journal, Gnip is one of a small number of Twitter partners that has access to what is known as the "fire hose," the full stream of tweets on the site since 2006. Gnip analyzes the tweets, which now number about 500 million a day, and then sells the information to customers. The acquisition likely signals that Twitter wants to dive deeper into analyzing the tweets that appear on its site.
Financial terms of the acquisition were not disclosed.
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Twitter also hired Google (GOOG) executive Daniel Graf as its new vice president of consumer products. Graf, who served as Google Maps director, replaces Michael Sippey, who left Twitter in January.
The stock closed up 11.43% to $45.54, a $4.67 increase from its previous close of $40.87. More than 22.4 million shares changed hands, well above its average volume of 13,553,300. The stock had a range of $40.76 to $45.55 for the day and holds a one-year range of $38.80 to $74.73.