N.Y. Comp. Codes R. & Regs. tit. 9 § 1645-2.10
The advisability of investing security deposits funds should be carefully considered by local agencies in view of the bookkeeping problems raised by the requirement in the New York State Real Property Law to the effect that the return, if any, on the investment of security deposits accrues to the tenant. The local agency, therefore, derives no benefit from the investment of such funds and the benefit to the individual tenants, in view of the size of most security deposits, is not only nominal, but out of all proportion to the expense to the local agency of keeping the records involved. In addition, the factor of possible loss on disposition of security deposit fund investments, which by law, are in the nature of trust funds, must be considered. Local agencies desiring, nevertheless, to invest security deposit funds should consult with the division and secure approval of the accounting system and procedures for recording and apportioning to the tenants accounts the interest earned.
N.Y. Comp. Codes R. & Regs. Tit. 9 § 1645-2.10