For 2018 through 2025, the miscellaneous itemized deduction for investment-related costs is not deductible. Before 2018, these amounts were subject to the 2%-of-adjusted-gross-income floor. After 2026, such amounts may be deductible (assuming total costs exceed the 2% floor).
The tax on the investment income in excess of $1,700 (may change after 2007) of a child under age 18, based on the parents’ marginal tax rate and computed on Form 8615.