(1) Assets held for investment purposes shall include:
(i) Any investment asset held by the plan on the last day of the plan year; and
(ii) Any investment asset which was purchased at any time during the plan year and was sold at any time before the last day of the plan year, except as provided by paragraphs (b)(2) and (b)(3) of this section.
(2) Assets held for investment purposes shall not include any investment which was not held by the plan on the last day of the plan year for which the annual report is filed if that investment falls within any of the following categories:
(i) Debt obligations of the United States or any agency of the United States;
(ii) Interests issued by a company registered under the Investment Company Act of 1940;
(iii) Bank certificates of deposit with a maturity of not more than one year;
(iv) commercial paper with a maturity of not more than nine months if it is ranked in the highest rating category by at least two nationally recognized statistical rating services and is issued by a company required to file reports with the Securities and Exchange Commission under section 13 of the Securities Exchange Act of 1934;
(v) Participations in a bank common or collective trust;
(vi) Participations in an insurance company pooled separate account;
(vii) Securities purchased from a person registered as a broker-dealer under the Securities Exchange Act of 1934 and listed on a national securities exchange registered under section 6 of the Securities Exchange Act of 1934 or quoted on NASDAQ;