This excerpt taken from the TPTX DEF 14A filed Jun 19, 2009.
If we decide to use a liquidating trust, interests of our stockholders in such a trust may not be transferable.
The interests of our stockholders in a liquidating trust set up by us may not be transferable, which could adversely affect your ability to realize the value of such interests. Even if transferable, the interests are not expected to be listed on a national securities exchange or quoted through the Nasdaq Stock Market, and the extent of any trading market therein cannot be predicted. Moreover, the interests may not be accepted by commercial lenders as security for loans as readily as more conventional securities with established trading markets. In addition, as stockholders will be deemed to have received a liquidating distribution equal to their pro rata share of the value of the net assets distributed to an entity which is treated as a liquidating trust for tax purposes, the distribution of non-transferable interests would result in tax liability to the interest holders without their being readily able to realize the value of such interest to pay such taxes or otherwise.