Recently patent portfolios have played key roles in M&A and litigation. This caught the attention of many people in business, including the bloggers of AllAboutAlpha.com, as they recently featured this interesting article:

Alpha Hunter Bags An Elephant Hidden in Plain Sight
There happens to be an investment universe with a current estimated value of $5.5 trillion sitting here in the United States.  That’s a bigger universe than the British or Japanese stock market.  In fact, with the current global value of equity markets at $55 trillion or so, this particular investment universe shows up as being worth about 10% of the world’s equity market cap.
...We speak of Intellectual Property (which we suppose would seem an oxymoron to anti-science presidential candidates) and patents, which are beginning to be analyzed and traded in their own right.