N.Y. Comp. Codes R. & Regs. tit. 3, § 22.5
(a) Investments shall be valued by reference to appropriate valuations applied by a generally accepted pricing service, or by the methods set forth in this section. All estimates, quotation sheets and valuations used for valuation shall be retained in the records of the common trust fund.
(b)
The following method shall be used in the valuation of investments: