There are two questions to separate: which investing app fits the parent's pattern, and which legal account structure holds the assets. The app and the account type are independent decisions.
How we ranked these
We built Slyce. Slyce is on this list because it wins the specific brief we built it for — spend-to-own custodial with no monthly fee plus Trump Account routing in one app. We're honest about where it doesn't win.
Criteria, in order:
- Account types supported. UTMA, 529, Trump Account, and how many can run in the same app.
- Cost. Subscription costs hit small custodial balances disproportionately.
- Match to spend-to-own vs. set-and-forget vs. teaching-focused. Different parents want different things.
- Parent UX. A custodial app's hardest job is staying out of the parent's way once it's funded.
1. Slyce — spend-to-own custodial plus Trump Account routing
What it automates: the parent links a card, sets a per-purchase rule for the child's account, and every eligible purchase triggers a fractional-share buy of the company you bought from — into the kid's custodial account, not the parent's. Parent-directed deposits to an eligible kid's federal Trump Account run in the same app.
Pricing: $0 per month.
Accounts: custodial (UTMA, state-dependent) and Trump Account routing for kids in the 2025–2028 eligibility window. The Trump Accounts guide covers the federal $1,000 seed and the $5,000 annual contribution cap.
Where Slyce wins for kids: custodial-from-day-one plus Trump Account routing in one app is a meaningful setup simplification for parents in the federal eligibility window[1]. Zero subscription compounds at small balances.
Where Slyce doesn't win: pre-launch. Pure 529 plans aren't supported — Slyce is a UTMA / brokerage app, not a state-sponsored 529 administrator.
2. Acorns Early — round-ups into a diversified custodial
What it automates: Acorns Early sits inside the Acorns app and routes round-ups into a diversified ETF portfolio held in a custodial UTMA[2].
Pricing: higher Acorns tier required (Gold or higher).
Accounts: UTMA via Acorns Early. Acorns offers IRA (Acorns Later) for the parent's separate retirement account.
Where Acorns Early wins: longest operating history of the round-up apps, broadly diversified, full IRA line elsewhere in the same app[3].
Where Acorns Early doesn't win: monthly subscription. No Trump Account routing. The custodial account holds ETFs, not specific brands — if you want the kid to own Apple because the family shops at Apple, Acorns doesn't deliver that.
3. Stash custodial (Stash+) — Stock-Back® on the parent's card
What it automates: Stock-Back® on the parent's Stash debit-card swipes can be routed to a custodial Stash+ account[4].
Pricing: Stash+ subscription.
Accounts: custodial UTMA via Stash+.
Where Stash custodial wins: if the parent already uses (or is willing to commit to) the Stash debit card, the rewards-to-custodial flow is straightforward.
Where Stash custodial doesn't win: requires committing to a debit card. Subscription on top. No Trump Account routing.
4. Greenlight — teaching-focused, not heavy investing
What it automates: Greenlight is primarily a kid-debit-card and chore-management app with an investing add-on. The investing module is parent-controlled with kid visibility.
Pricing: monthly subscription.
Accounts: custodial brokerage tied to the Greenlight family plan.
Where Greenlight wins: if "teach my kid about money" is the brief and investing is a secondary feature, Greenlight is the category leader for parent-controlled financial education tools. The chore tracking and kid-debit-card mechanics are tightly integrated.
Where Greenlight doesn't win: investing is shallow compared to dedicated brokerage apps. Subscription is on the higher end. No Trump Account routing.
5. Fidelity Youth — bank-grade, no-frills
What it automates: Fidelity Youth is a bank-grade brokerage account for teens (typically 13–17). It's a real Fidelity brokerage account with no monthly fee and full Fidelity research tools.
Pricing: $0 per month.
Accounts: Fidelity Youth Account (teen brokerage). Separate from Fidelity custodial UTMA, which Fidelity also offers.
Where Fidelity Youth wins: the Fidelity research tools, the no-fee structure, and the bank-grade safety/SIPC story. If you want a real brokerage, not a fintech wrapper, Fidelity is the established option[5].
Where Fidelity Youth doesn't win: no spend-to-own automation. No Trump Account routing as of this writing. Designed for teens who can self-direct, not for spend-driven custodial automation for younger kids.
On the account-structure side
Independent of the app, the legal-structure choices are:
- UTMA / UGMA. Custodial brokerage account under state law. The custodial accounts guide covers the mechanics. UTMA vs 529 walks the comparison with 529 plans.
- 529 plan. State-sponsored education savings with state-level tax advantages. Not held inside the apps above — administered by state-selected program managers.
- Trump Account. Federal program for kids born 2025–2028. $1,000 federal seed, $5,000 annual family contribution cap, plus employer matches and state programs. See the Trump Accounts guide.
- Custodial Roth IRA. Available if the kid has earned income. None of the consumer custodial apps above is the right administrator for a custodial Roth — you'd open one at Fidelity or Schwab.
The kiddie tax applies to a child's unearned income above an annual threshold, regardless of which app holds the account[6].
Verdict by parent goal
- Want spend-to-own custodial with Trump Account routing: Slyce.
- Want round-ups into a diversified custodial: Acorns Early.
- Want Stock-Back® on the parent's debit card to fund the kid's account: Stash custodial.
- Want a teaching-focused chore-and-money app: Greenlight.
- Want a bank-grade brokerage for a teen: Fidelity Youth.
The 2025–2028 federal Trump Account is a meaningful additional layer. Run your kid's specifics through the eligibility checker for the full federal-and-state stack.
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Frequently asked
- What's the best investing app for a kid?
- Depends on what you want automated and what kind of account you want to open. For spend-to-own custodial with no monthly fee plus Trump Account routing, Slyce. For round-ups into diversified ETFs, Acorns Early. For Stock-Back® on a debit card the parent uses, Stash custodial. For pure no-frills bank-grade brokerage, Fidelity Youth.
- What's the difference between a UTMA and a Trump Account?
- A UTMA is a custodial account established under state law that holds any assets a parent contributes for the child until the child reaches the age of majority. A Trump Account is a federally-created account for kids born 2025–2028 with a $1,000 federal seed and a $5,000 annual family contribution cap. They're different account types with different rules — a kid in the eligibility window can have both.
- Does the kiddie tax apply to all of these?
- The kiddie tax applies to a child's unearned income above an annual threshold, regardless of which app holds the UTMA or 529. Trump Accounts have their own tax treatment under the OBBBA statute. Consult a tax professional for specifics — the numbers change year over year.
- Can I open a custodial account on these apps if I'm not the legal parent?
- Most apps require the custodian to be a parent or legal guardian. Some allow grandparents to fund a UTMA where the parent is the custodian. The legal custodian on the account is the person who can make investment decisions until the child reaches majority — read each app's custodial-account terms before assuming.
- What happens to a custodial account when the kid turns 18?
- For a UTMA, the assets transfer to the child at the age of majority defined by state law (18 or 21 depending on the state). For a Trump Account, the rules under OBBBA control the transfer — the federal program's rollover rules differ from a standard UTMA. The custodial account at any of these apps converts according to whichever account-type rules apply.
Keep reading
Slyce Editorial
Published May 3, 2026 · Updated May 3, 2026