You may want to look into setting up a trust for the child. You can then create a portfolio of mutual funds, annuities, etc. that you will have control over. Just name the trust as your beneficiary. If anything happens to you, the trustee of the trust will then act according to your instructions. If you are still living when yuor grandchild turns 25, you can liquidate the assets in the portfolio and gift them to your grandchild.