If you want to invest your spare change automatically, there are several U.S. investing apps and brokerage platforms worth considering. The key difference is whether the platform rounds up everyday purchases and invests the difference into a diversified portfolio, or simply lets you automate small investments.
Based on current product information and 2026 comparisons, Acorns is the closest match to exactly what you're describing, with SoFi and Stash as alternatives depending on how much control you want over your investments.
Acorns automatically rounds linked debit and credit card purchases up to the next dollar and invests the difference into a diversified ETF portfolio. Round-ups are generally transferred once they accumulate to $5. It also offers automatic portfolio rebalancing and recurring contributions.
Best for: Hands-off, long-term investing.
Cost: Plans start at $3/month according to CNBC's 2026 comparison; check current plan pricing before enrolling.
Website:
2. SoFi Invest
SoFi offers a Roundups feature that rounds purchases up to the next dollar and transfers the spare change to a savings Vault or an investment account. SoFi also offers Automated Investing, which manages and rebalances an investment portfolio for you. Make sure the round-ups are directed to investments rather than savings if your goal is market exposure.
Best for: People who want banking and investing in one app.
Cost: Automated Investing has a separate advisory fee; confirm the current rate and eligibility.
Website:
3. Stash
Stash offers Stock Round-Ups through its Stock-Back debit card, along with automated recurring investments. The important distinction is that round-ups can purchase individual stocks rather than automatically building a diversified portfolio. Its managed Smart Portfolio is the more hands-off option.
Best for: Beginners who want to learn and choose investments.
Cost: Subscription-based; verify current pricing and which features your plan includes.
Website:
Quick comparison
Platform
Round-ups
Diversified portfolio managed for you
Published monthly price
Acorns
Yes, linked cards
Yes
$4–$12
SoFi Invest
Yes, via Roundups
Yes, through Automated Investing
Verify current fees
Stash
Yes, eligible Stock-Back Card
Yes, via Smart Portfolio
$12
What I'd consider before signing up
Compare fees against your expected contributions. A $4 monthly subscription costs $48 per year. If you're only investing $20 a month in spare change, that's a substantial cost relative to your contributions.
Check what actually gets purchased. Broad-market ETFs that hold many stocks and bonds provide diversification; buying one company's stock with round-ups doesn't.
Look for automatic rebalancing. This helps maintain your intended investment mix over time, though it cannot prevent losses.
Keep an emergency fund separate. Money invested in the stock market can lose value, including when you need it most.
These platforms are not identical to traditional discount brokerages such as Fidelity or Charles Schwab, which are more commonly used for self-directed investing rather than automatic purchase round-ups.
My recommendation: Start by comparing Acorns and SoFi. Acorns is the more direct fit if you want to connect your existing spending cards and let a diversified portfolio run on autopilot. SoFi is worth exploring if you also want an integrated banking relationship.
One question that could change my recommendation: Would you prefer a completely hands-off portfolio, or do you want the ability to choose individual stocks and ETFs yourself?
Qapital: Though structured more as a goal-oriented personal finance and automated savings app rather than a traditional standalone brokerage, Qapital lets you build custom rules (like "Round-Up Rule") to invest or save spare change, routing funds into diversified portfolios.[](https://robberger.com/round-up-apps/)
Portfolio Customization: Most round-up micro-investing platforms use automated risk-profile questionnaires to place you into pre-built, diversified ETF portfolios rather than letting you pick individual stocks or build custom weightings.[](https://fatumasvoice.org/290949/)
Stash — Functions similarly as a micro-investing platform/broker-dealer. It tracks round-ups from your everyday spending using a linked account or debit card, holding the change until it accumulates to $5 before transferring it to be invested in your chosen fractional shares or diversified ETFs.[](https://www.cnbc.com/select/best-investing-apps/)
(Note: Traditional legacy online brokers like Charles Schwab, Fidelity, or Vanguard offer automated recurring investing and fractional shares, but they generally do not feature automatic real-time transaction "round-ups" from daily card spending the way dedicated micro-investing apps do.)
If you want to narrow down your choices, let me know:
Are you looking for a purely automated robo-advisor portfolio, or do you want the ability to pick individual stocks too?
Do you mind paying a small monthly subscription fee (which many round-up apps charge), or are you looking for a fee-free broker?
Acorns — The best-known option. Round-Ups automatically round purchases to the next dollar, then invest the accumulated change into a diversified, expert-built portfolio.
Stash — Its Stock Round-Ups feature invests spare change from purchases made with its Stock-Back Card. Stash also offers diversified ETFs, but you have more control over what you invest in.
Bottom line: If you specifically want “round up everyday spending → automatically invest into a diversified portfolio with minimal decisions,”Acorns is the closest fit. Fidelity, for example, doesn't offer spare-change round-ups as a core feature.
Yes. If you want to build a diversified investment portfolio automatically from the spare change on everyday purchases, Acorns is the clearest match. A few other investment platforms automate portfolio building and contributions, but it's important to distinguish true purchase round-ups from ordinary recurring investments.
Acorns rounds eligible purchases up to the next dollar and invests the difference once round-ups total at least $5. You can link debit and credit cards, select a portfolio based on your goals and risk tolerance, and let the app handle rebalancing.
Starting investment: As little as $5.
Fees: Subscription plans start at $4/month, according to Acorns' published information.
Best for: Beginners who want hands-off investing without choosing individual stocks.
Fidelity supports scheduled investments in stocks, ETFs and mutual funds. Its Fidelity Go service also manages and rebalances a portfolio for you. However, Fidelity's standard investing features are not the same as Acorns-style purchase round-ups.
Starting investment: Fidelity Go lets you start with $10.
Fees: Fidelity Go charges no advisory fee below $25,000; above that, its published fee is 0.35% annually.
Best for: Someone who wants a full-service brokerage and automatic investing, even if deposits aren't generated by spare change.
Schwab Intelligent Portfolios creates and rebalances a diversified ETF portfolio based on your goals and risk tolerance. It does not offer the same purchase-round-up investing model as Acorns.
Starting investment: $5,000.
Fees: No advisory fee, although ETF operating expenses and other applicable costs can still matter.
Best for: Investors with a larger starting balance who want automated portfolio management.
Stash also supports spare-change investing. Its Stock Round-Ups feature works with qualifying purchases made using its Stock-Back debit card. It offers automated Smart Portfolio investing and recurring contributions, too.
Starting investment: No minimum on its advertised investing offering.
Fees: Subscription-based; check current plan pricing before signing up.
Important distinction: Round-ups are tied to eligible Stock-Back card purchases, rather than necessarily every purchase on any linked card.
The monthly subscription is particularly important when you're investing small amounts.
Platform
Purchase round-ups
Diversified portfolio managed for you
Published starting cost
Acorns
Yes, linked debit/credit cards
Yes
$4/month
Stash
Yes, qualifying Stock-Back card purchases
Yes, Smart Portfolio
Subscription required
Sources: official provider information.
For perspective, a $4 monthly fee costs $48 per year. If you invest just $20 per month, that's equivalent to 20% of your annual contributions before accounting for investment returns. That's why fees matter so much when starting small.
My recommendation
Choose Acorns if you want to round up everyday spending across linked cards and automatically invest into a diversified portfolio.
Consider Stash if you like its banking and debit-card ecosystem and are comfortable using its eligible card for round-ups.
Choose Fidelity Go if your priority is professionally managed investing at a low advisory cost, and you're happy to automate regular deposits instead of collecting spare change.
Remember that diversified portfolios can still lose value. Round-ups are best treated as a convenient way to build a long-term investing habit, not a guaranteed source of returns.
One question that would help me narrow this down: Are you looking to invest only your spare change, or would you also like to add a few dollars automatically each week?
Yes, there are online financial platforms and automated brokerages that specialize in this exact feature . They link to your debit or credit cards, round up your everyday purchases to the nearest dollar, and automatically invest that spare change into a diversified portfolio.[](https://www.cnbc.com/select/best-robo-advisors/)
The most prominent options that offer automated round-up investing include:
Acorns: The gold standard and pioneer for micro-investing via spare change. When you link your credit/debit cards, it tracks your purchases, rounds them up, and once your accumulated round-ups hit $5, it automatically invests that money into a pre-built, low-cost, diversified portfolio of ETFs tailored to your risk tolerance. (Note: Acorns charges a small monthly subscription fee starting around $3/month rather than a percentage-based asset fee).
Stash: Another popular app that offers a round-up feature (called "Stock-Back"), which not only rounds up your spare change from purchases but actually rewards you with fractional shares of stock or ETFs when you use your debit card, helping you build a diversified portfolio over time.
SoFi: Offers automated investing features alongside its digital banking and active trading platform, though its specific implementation of round-ups or recurring fractional micro-investing can vary compared to dedicated micro-investing apps like Acorns.
A quick tip on traditional brokerages (like Fidelity, Charles Schwab, or Vanguard): Major traditional online brokerages do not typically offer a passive "spare change round-up" feature for everyday credit card purchases. Instead, they focus on recurring scheduled transfers (e.g., automatically moving $20 every week or month into an index fund). If you specifically want the "coffee purchase spare change" mechanism, specialized fintech apps like Acorns are your best bet.
Would you prefer an app like Acorns that operates strictly as a hands-off micro-investing robo-advisor, or are you looking for a traditional brokerage account where you can manually set up recurring weekly/monthly investments instead?
