N.Y. Comp. Codes R. & Regs. tit. 20, § 154.7
(a) Where an individual or a trust changes resident status during the taxable year, the net capital gains and losses attributable to such individual or such trust are to be computed separately for the resident period and for the nonresident period covered by the New York State income tax returns required under this Part. In each case the computation of the capital gain or loss to be reported is to be made in the same manner as the corresponding Federal computation and on the same basis as if the taxable year of such individual or such trust for Federal income tax purposes were limited to the taxable period covered by the applicable New York State income tax return, except that:
(b) See section 154.5 of this Part concerning New York minimum taxable income where an individual or a trust has a Federal item of tax preference for a capital gain deduction which is attributable to either the period of New York State residence or nonresidence.
(c)