How a zeroed-out GRAT works
You transfer $10M of an appreciating asset into a 2-year GRAT. The IRS values your retained annuity at $10M plus the §7520 hurdle rate. The remainder gift is calculated as zero. If the asset grows to $14M, the annuity returns $10M plus interest to you, and the remaining $3.5M+ passes to the trust beneficiaries with no gift tax used.