Investing apps › Best app for under $500

Best investing app if you are starting with under $500

Fees verified against each platform's official pricing page · by FinanzaX Decide

Two of the four apps we compare charge a flat monthly fee. Two charge nothing. That distinction barely matters once you have a few thousand dollars invested. Under $500, it is close to the single biggest cost you will pay this year, and it has nothing to do with performance.

This is not financial advice. It is a comparison of published fees at specific balance levels. See our full disclaimer.

The flat fee is a tax on small balances

Acorns' Bronze plan and Betterment's Digital plan both charge a fixed monthly fee instead of a percentage: $4/month for Acorns, $5/month for Betterment when your recurring deposit is under $200/month. A flat fee does not care how much money it is taken from, so the smaller your balance, the larger a bite it takes.

A 24% annual fee is not a rounding error. It is worse than what most people pay in credit card interest. At $200, Acorns' Bronze plan and Betterment's Digital plan would each need the market to hand them a historically exceptional year just to break even against their own fee.

Where the flat fee stops mattering

The fee is fixed in dollars, so its effective rate keeps falling as your balance grows. Acorns' $48 a year drops under a 1% effective rate once your balance passes roughly $4,800. Betterment's $60 a year crosses that same rough line around $6,000, and Betterment's own pricing already switches it to a 0.25% annual rate once your balance reaches $24,000, or earlier if you set up a recurring deposit of $200 a month or more (see the growth calculator to run your own numbers month by month). Below those thresholds, the flat fee is working against you every single month.

So why would anyone pick the flat-fee option under $500?

Because cost is not the only variable. Acorns' entire product is automatic Round-Ups investing: it rounds up your everyday purchases and invests the spare change without you doing anything else, which is a real behavioral advantage for someone who has never managed to invest consistently on their own. Betterment's flat fee buys automatic tax-loss harvesting from day one, a feature Robinhood and Webull do not offer at any price on their standard plans. Paying a high effective rate for a feature you will actually use can still be the right trade for a specific person; the mistake is not knowing you are paying it.

The honest tradeoff, once fees are out of the way

Robinhood and Webull charge nothing at any balance, so if fees alone decided this, they would win every time under $500. What you give up is automation: both are self-directed, so you pick your own investments and get no round-ups, no automatic rebalancing, and no tax-loss harvesting. Robinhood also carries the heaviest FINRA regulatory history of the four (see the full regulatory record), and Webull's possible $5/month inactivity fee is not yet confirmed by a direct render of its official page, so treat it as a real but unverified risk rather than a settled fact.

So: what should you do

1. If you want to invest small amounts automatically and will not do it manually, Acorns' Round-Ups is worth its fee even under $500, as long as you know the real effective rate you are paying.
2. If cost is the only thing that matters and you are comfortable picking your own investments, Robinhood or Webull charge nothing at this balance.
3. If you specifically want automatic tax-loss harvesting and can commit to a $200/month recurring deposit, Betterment's percentage rate kicks in immediately instead of the flat fee.
4. Once your balance clears roughly $5,000 to $6,000, run your own numbers again: the flat-fee math looks completely different above that line.