N.H. Rev. Stat. § 31:25-a
Any security which at the time of its purchase under RSA 31:25 constituted a legal investment for any bank chartered by this state to engage in a banking business or for trustees of trust funds under the laws and conditions then existing may be retained notwithstanding the fact that, because of changes in the law relating to legal investments or because of conditions arising subsequent to the purchase of such security, its purchase might not then be legal; provided, however, that no such security that is not a prudent investment under the circumstances existing at the time of its retention and thereafter may be retained by the trustees; and provided further, that the aggregate total of the market value of all securities retained under this section shall not exceed 20 percent of the total market value of all the investments held by the trustees.
RSA 31:25-a
1983, 118:1, eff. May 25, 1983. 1997, 181:2, eff. Aug. 16, 1997. 2001, 54 : 2 , eff. Jan. 1, 2002. 2021, 65 : 8 , eff. Aug. 3, 2021.