Shares of RPX (RPXC) opened today at $13.88, up 2.81%, after rising 5.6% last Wednesday on rumors from two sources that the defensive patent aggregator is a takeover target.

Richard Lloyd of the IAM blog broke the story on December 12, saying the a private group had offered $16.25 per share for the company, or $800 million, a 27% premium.

But some observers doubt whether RPX can fetch that high of a premium. Don Lonkevetch writing in this morning’s Patent Investor said:

“That’s because San Francisco-based RPX’s business has been hurt by its own past success in combatting non-practicing entities and the overall decline in patent litigation since the American Invents Act of 2011 made it cheaper and easier for companies to invalidate patents…

“As a result, big tech companies who have been among RPX’s biggest clients have grown increasingly reluctant to rely on RPX to put together syndicates to keep patents out of the hands of NPEs.”

The Patent Investor cites an anonymous source familiar with RPX (short for Rational Patent Exchange) who suggests  the company is worth about $12 per share.

Below IPO Price

RPX is already up about 24% this year, but is still trading well below its 2011 IPO price of $19 per share. Founding CEO John Amster left the company earlier this year after his suggestion to take the company private at $11 per share were nixed.

Baird analyst Jeffrey Meuler reiterated his Outperform rating last week and $15 price target on RPX Corp.

Earlier in the year, on March 8, CNA Finance reported that “Early this morning, stories started breaking that RPX Corp may soon be acquired. In fact, according to some of the reports, the company has received several offers from private equity companies to take it out of the public sector.”

On that day RPX shares rose 15%. Thus far, the RPX board has not commented.

If RPX were to be acquired at a significant premium to its current $668 million market capitalization, it would be a boost of confidence not only for the company’s shares and public IP companies (PIPCOs), but for patent holders in general. It could be a signal that patent values are headed higher.

On Thursday, USPTO Director Nominee Andrei Iancu was unanimously approved by Senate Judiciary Committee, signaling a further distance from the Michelle Lee-led USPTO that saw a dramatic rise in invalidations before the Patent Trial and Appeal Board.

Image source: rpxcorp.com; laborcosting.com