We first highlight which institutional investors bought, sold, or held ParkerVision stock over the last two years.

ParkerVision changed the composition of its top tier (>500,000 shares) investors several times.  Gone are the following investors:

• Arbor Capital Management was the largest shareholder in December 2004 but fully divested itself by June 2005. 
• Leucadia National became a shareholder in 2000, and divested itself complete by December 2006.   
• Special Situations Fund (Marxe, Austin & Greenhouse) that first invested in the 2005 private placement, and subsequently almost doubled its position in late 2005, but divested itself complete by December 2006.
• Kern Capital Management started buying in late 2005, and fully divested itself within less than a year (mid 2006) of its initial investment.  

Heartland Advisors bought into the 2006 private placement, and has slowly been divesting itself of its original purchase.  However, a few firms are actually increasing their holdings:

• Wellington Management Company has gradually increased its position five times since 2004.  As of today, Wellington holds the largest institutional investor position.
• KOM/Knoll Capital Management, as well as Barclay’s Bank have continued to increase their position significantly over the past year.
• Gem Investment Advisors, LLC, recently (March 2007) purchased 1,221,806 shares. This also means that someone else sold.

ParkerVision has had an eclectic assortment of past and present investors.  Some examples of past and present investors are listed below, with excerpts from  articles.

Banco del Gottardo
The bank has had links to Al-Qaeda, Saddam Hussein, and Russian bio-weapons traders:
http://www.washingtontimes.com/upi-breaking/20040602-103911-3005r.htm
http://www.spitfirelist.com/f463.html
http://www.american-reporter.com/2,600/1632.html

Amir L. Ecker
Amir was named as a respondent in an NASD complaint alleging that he excessively traded in the account of a public customer and purchased an unsuitable concentration of speculative securities in the account. The complaint also alleges that Ecker exercised discretion in the customer’s account without prior written authorization from the customer and prior written acceptance of the account as discretionary by his member firm. (NASD Case #C9A000007)
http://www.stockbroker-fraud.com/nasdr_data.php?eid=5152&tid=8981

Sherleigh Associates
A firm that has a history of initiating class action lawsuits as well as pump and dump tactics that led to SEC fines:
http://www.gilardi.com/pdf/ergo1not.pdf
http://www.gilardi.com/pdf/cohnot.pdf
http://lw.bna.com/lw/19990323/2273.htm
http://www.businessweek.com/1997/38/b3545114.htm 
http://www.thestreet.com/stocks/eileenkinsella/1482260.html
http://www.keepmedia.com/pubs/BusinessWeek/2000/12/25/30683?extID=10026
http://www.primezone.com/newsroom/news_releases.mhtml?d=55232

Special Situations
The hedge fund, run by Austin Marxe and David Greenhouse, has or had an interest with 229 registrant companies.  The fund has a reputation for “pump and dump” tactics, as well as trading microcap stocks of troubled companies on the bulletin boards and pink sheets.   Their investments do not appear to have significant longevity.  An interesting common thread between the companies that they invest in appears to be “net loss”, which is consistent with their investment in ParkerVision. 

An interesting question to pose is whether or not Special Situations and Wellington share a relationship.  They do have a list of mutual investments:
World Heart Corporation, SeaChange Intl (SEAC), Ciphergen Biosystems (CIPH), Meade Instruments (MEAD), RedEnvelope (REDE), Quantum Fuel Systems, Technologies Worldwide (QTWW), Quovadx (QVDX), Zonagen (ZONA), 1-800 contacts inc (CTAC), US Physical Therapy (USPH), Skymall (dead)

Some examples are listed below, with excerpts from the articles:
GoAmerica - http://www.smartmoney.com/onedaywonder/index.cfm?story=20041112
Is this s pump and dump?
Quote:
"In the course of one week, the stock goes up more than 300%," says Cohan, the management consultant. "If you look at the financial profile of the company, I don't think the fundamentals improved 300% this week. There is a big gap in the performance of the stock and the performance of the fundamentals. If there was ever a great example of how a stock doesn't reflect the underlying business, this is it."

Tarantella - http://www.findprofit.com/archive/4089.html - no longer listed (dead?)
So with this in mind, we were intrigued by a new 13D filing that hit the tape last week disclosing that Austin Marxe and David Greenhouse of the Special Situations funds had amassed a sizeable stake in a small software shop called Tarantella (TTLA). From a quick check I did earlier this afternoon, TTLA was delisted from Nasdaq earlier this year and is now trading on the lowly pink sheets due apparently to some accounting issues that knocked the firm off course.

Boots & Coots - http://majorbarbara.blogspot.com/2003_03_23_majorbarbara_archive.html
You'll recall that Boots & Coots was set to make a big splash last week, but for a mysterious loan that threatened to sink the company at its most promising hour. Sure enough, the price climbed rapidly as war fever set in -- and showed the kind of volatility one might anticipate under the circumstances. The price really started to tank when CNN bravely trumpeted to small investors Beware The Hellfighter Stock. Kudos to CNN for running that little caveat -- on Thursday -- long after many people had made good faith investing decisions on some very spotty disclosure.

Smart investors, like Austin W. Marxe and David Greenhouse of those big "Special Situations Funds," got out of Boots & Coots some time ago. In fact, it seems that most of the institutional investors were selling, not buying, in the run-up to the war.
And, lo and behold, the oil wells so far haven't ignited by the dozen. Boots and Coots isn't headed straight for boomtown after all.

PlanetCAD - http://www.upfrontezine.com/2001/upf-275.htm
The co-owner of the 9.7% shares is Austin Marxe, owner of the 60-year-old AWM Investment Company. Marxe and Greenhouse also own the Special Cayman Fund, have invested in a similar set of other companies, and hold many shares indirectly. The common thread among the companies in which they invest appears to be "net loss."

First Virtual Communications: FVCC
Another defunct Marxe and Greenhouse investment.  Note message 45783 from the Yahoo BB: “Losers big time in FVC,... I don't expect they will salvage very much of their investment as a result of the pending class action lawsuits...
SELL, SELL, SELL!!”