UPDATE, 4 PM: Twitter says (of course, on Twitter) that it has priced its initial public offering of 70,000,000 shares of its common stock at $26 a share — higher than estimates earlier this week of $23 to $25. The stock is expected to begin trading tomorrow on the New York Stock Exchange under the symbol TWTR.

PREVIOUS, MON. NOV. 4 PM: A mixed morning for the company newswise. Twitter says in an SEC filing that it intends to price its stock at between $23 and $25 a share — up from its previous target of $17 to $20. The change values the company at about $17B+, up from about $11B. Sounds like a lot to pay for a company that’s losing money. But it’s consistent with the values that Wall Street analysts have been putting on the company. For example, BTIG’s Richard Greenfield says today that he expects the IPO price to come in “at the bottom-end of the new range” — and even before this morning he “saw a path to $30 [a share] over the next year.” Others also have been optimistic. Last week Sterne Agee’s Arvind Bhatia said the stock could go to $32 over the next two years. And Pivotal Research Group’s Brian Wieser put a target price of $29 on Twitter shares.

But Twitter also disclosed that IBM recently wrote saying that the social media company is infringing on at least three patents and invited execs “to negotiate a business resolution of the allegations.” Twitter says that it believes it has “meritorious defenses to IBM’s allegations,” but can’t guarantee that “we will be successful in defending against these allegations or reaching a business resolution that is satisfactory to us.”