Cadus is a tiny company that barely trades, so this is purely an idea for (small) PA's. 

Cadus Corporation (OTC: KDUS) is a tiny shell company trading at a 21% discount to its cash, net of all liabilities.  This highly illiquid stock is trading for $1.42 per share while it has $1.80 per share of net cash, in addition to patents and drug discovery technologies that I'm assuming are worthless, as well as $2.13 per share of net operating loss and research and development credit carryforwards that could potentially be valuable.  The company has been looking to make an acquisition ever since it sold its primary drug discovery assets to OSI Pharmaceuticals ("OSI") in 1999.

Yes, Cadus has been a looking for an acquisition for over a decade.  In 2009, a special committee of board members was formed to evaluate a potential acquisition that ultimately fell through.  Carl Icahn is the largest shareholder, but it is clearly not a high priority for him, considering its small size.  Carl's son, Brett Icahn, replaced Carl on the board last year.

Cadus was actually the subject of a Wall Street Journal article last year in which Carl Icahn was quoted.

"We've been looking assiduously for three years for opportunities," he told me this week. "But I don't want to make a bad acquisition and lose the cash." He added, "I strongly believe that in today's type of market we will find a company [to buy] fairly soon."

Furthermore, Mr. Icahn says, if Cadus distributed its cash to shareholders, it would have no money for an acquisition, losing the opportunity to use its tax benefits directly. "I don't want to waste $25 million," he says. Of course, Cadus could still be acquired by another firm that could make use of the tax break.

http://online.wsj.com/article/SB10001424052748704913304575371370117600364.html

So, take that for what it is worth.  If or when an acquisition is announced, I would expect the stock price to approach at least net cash, or perhaps a bit more if the tax assets can be utilized.  Cadus could also be acquired or finally decide to liquidate.  The cash burn rate is about $0.03 or $0.04 per share annually.  The company has no employees and even the CEO is a consultant.  His salary is $25,000 per year.  Board members earn $3,000 per year.  Clearly, milking the company for cushy board seats or lavish perks is not the reason why an acquisition has not occurred for so long.

Carl Icahn owns about 5.3 million shares or 40% of the company.  He bought about 298,000 shares in early 2009.  Moab Partners and GlaxoSmithKline own 13% and 5%, respectively.  A board member purchased 50,000 shares in December for $1.35 per share.

Risks

The most obvious risk is that the board never finds an acquisition and the modest cash burn continues for several years.  The board could also make a terrible acquisition and squander the cash and/or tax assets.  The IRR on this investment may not be great, but it also should not be negative.  The stock is also entirely uncorrelated with the market.