Money for Minors

The Compound-Growth Math Behind Kids' Investment Accounts

New "Trump Accounts" seed newborns with $1,000 of index-fund investments. Whatever you think of the politics, the underlying finance — starting investments at age 0 — is worth understanding. Grow the money tree below.

Grow the Money Tree

Each ring of golden fruit is roughly $5,000 of value at age 18. Move the sliders and watch the tree — and the split between what was contributed vs. what compounding added.

drag to rotate
projected balance
money put in
growth earned

What are "Trump Accounts"? The neutral facts

These accounts join an existing family of options: 529 plans (tax-free for education), custodial UTMA/UGMA accounts (flexible, taxed to the child), and custodial Roth IRAs (needs earned income; tax-free at retirement). The right pick depends on the goal — none is automatically "best."

Worked example: why age 0 beats age 25

PlanTotal contributedValue at 65 (7%/yr)
$1,000 at birth + $50/mo until 18, then nothing$11,800≈ $250,000
Nothing until 25, then $200/mo for 40 years$96,000≈ $479,000
Both combined$107,800≈ $729,000

The child plan contributes 8× less money yet ends up with more than half as much — because its dollars compound for 47–65 years. That's the whole lesson: time in the market is the most powerful variable, more than the contribution amount or even the return rate.

Caveats worth teaching kids too: 7% is a long-run average (the S&P 500's inflation-adjusted historical average) — real paths swing wildly; fees compound against you exactly the way returns compound for you; and locked accounts trade flexibility for discipline.

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