N.Y. Const. art. XVI, § 3

Moneys, credits, securities and other intangible personal property within the state not employed in carrying on any business therein by the owner shall be deemed to be located at the domicile of the owner for purposes of taxation, and, if held in trust, shall not be deemed to be located in this state for purposes of taxation because of the trustee being domiciled in this state, provided that if no other state has jurisdiction to subject such property held in trust to death taxation, it may be deemed property having a taxable situs within this state for purposes of death taxation. Intangible personal property shall not be taxed ad valorem nor shall any excise tax be levied solely because of the ownership or possession thereof, except that the income therefrom may be taken into consideration in computing any excise tax measured by income generally. Undistributed profits shall not be taxed.