Quick Answer
- Automating ETF buys needs two features together: recurring purchases (scheduled, hands-off) and fractional shares (so the whole deposit gets invested, not just whole shares).
- M1 Finance is purpose-built for it: set target percentages, and every deposit is invested and auto-rebalanced. Fractional shares are the default.
- Fidelity and Robinhood both support recurring ETF buys plus fractional shares, so a fixed dollar amount goes in automatically.
- Schwab supports recurring purchases, but its fractional program covers S&P 500 stocks, not all ETFs, so exact-dollar ETF automation is limited.
- Vanguard's automatic investing is strongest for its own mutual funds; fractional purchases are limited to Vanguard ETFs.
What Automatic ETF Investing Actually Requires
Two features have to work together, and a broker can have one without the other.
Recurring purchases let you schedule a buy, say $200 into VTI on the 1st of every month, that executes on its own. Most major brokers now offer this for ETFs, so on its own it is not the differentiator people assume.
Fractional shares are what make the schedule actually work. Without them, a recurring purchase can only buy whole shares. Put $200 into a fund trading at $150 and you buy one share, leaving $50 sitting in cash until it slowly accumulates enough for the next whole share. With fractional shares, the full $200 goes to work every single time. That is the entire point of a hands-off, dollar-cost-averaging plan, so a broker that offers recurring buys but not fractional ETF shares only does half the job.
Before opening an account to automate ETF investing, check one thing: does the broker offer fractional shares on the ETFs you want, not just on a short list of large stocks? That single detail separates true exact-dollar automation from a plan that leaves cash stranded.
The Brokers, Compared for Automation
All of these charge $0 commission on ETF trades, so the real differences are whether recurring buys and fractional shares work across a broad set of ETFs. Details below are current as of 2026 and change over time; verify on each broker's own site before you open an account.
| Broker | Recurring ETF buys | Fractional ETF shares | Account minimum | Best fit for |
|---|---|---|---|---|
| M1 Finance | Yes, core feature | Yes, by default | $100 to start investing | Fully automated, rules-based portfolios |
| Fidelity | Yes | Yes, wide range of ETFs | $0 | All-in-one: automation plus a full brokerage |
| Robinhood | Yes | Yes, from $1 | $0 | Simplest hands-off setup for beginners |
| Schwab | Yes | Limited (S&P 500 stocks, not all ETFs) | $0 | Whole-share recurring; deep full-service broker |
| Vanguard | Yes | Limited to Vanguard ETFs | $0 | Automatic investing into Vanguard's own funds |
Account minimums and fractional-share coverage change over time. Confirm current terms on each broker's site. This is educational information, not a recommendation.
Broker by Broker
M1 Finance: built for automation
M1 is the only broker here designed around automatic investing from the ground up. You build a "pie" of ETFs with target percentages, set up recurring deposits, and every dollar is invested and rebalanced toward your targets automatically, in fractional amounts. If your goal is a set-it-and-forget-it portfolio that maintains its own allocation, this is the cleanest fit. The trade-off is that M1 is less useful as an active trading account, and it has a $100 minimum to begin investing.
Open an account at M1 Finance →Fidelity: automation inside a full brokerage
Fidelity pairs recurring investments with fractional shares across a wide range of ETFs, so you get true exact-dollar automation without giving up a complete, full-service brokerage. There is no account minimum. For most people who want to automate ETF investing but also keep a normal brokerage, retirement accounts, and research in one place, Fidelity is the pragmatic default.
Open an account at Fidelity →Robinhood: the simplest hands-off setup
Robinhood offers recurring buys and fractional shares from as little as $1, in an interface built to remove friction. For a beginner who wants to schedule a weekly or monthly ETF purchase and not think about it, it is the fastest to set up. It is a lighter platform than Fidelity or Schwab, with less depth on research and account types.
Open an account at Robinhood →Schwab and Vanguard: capable, with real limits
Schwab supports recurring ETF purchases and is an excellent full-service broker, but its fractional-share program (Stock Slices) covers S&P 500 stocks rather than all ETFs. That means recurring ETF buys generally purchase whole shares, leaving some cash uninvested between purchases. Vanguard's automatic-investment feature has long been strongest for its own mutual funds, which support scheduled exact-dollar purchases; for ETFs, fractional buying is limited to Vanguard's own funds. Both are strong brokers, but for broad, exact-dollar ETF automation they trail M1, Fidelity, and Robinhood.
If you are set on Vanguard or want the simplest possible automation, a low-cost index mutual fund can be easier to automate than an ETF: mutual funds have always supported scheduled purchases in exact dollar amounts, with no fractional-share question. The ETF vs mutual fund guide covers when one structure beats the other.
How to Set It Up
The mechanics are similar across brokers once you have picked one:
- Open and fund the account, and link your bank for automatic transfers.
- Pick your ETF or a small set of them. A simple 3-fund portfolio is a common starting point.
- Find the "recurring investment," "automatic investment," or "schedule" option on the fund or in account settings.
- Set the amount, the frequency (weekly, biweekly, or monthly, often aligned to payday), and the start date.
- Confirm fractional shares are on, so the whole amount is invested each time.
Once it runs, the value of automating is behavioral: it removes the decision to invest from each month, which is the decision people most often skip. See how to buy ETFs for the full first-purchase walkthrough.
Common questions
M1 Finance, Fidelity, and Robinhood all support automatic, recurring ETF investing with fractional shares, which lets you invest an exact dollar amount on a set schedule. M1 is purpose-built for it: you set target percentages and every deposit is invested and rebalanced automatically. Fidelity supports recurring investments and fractional shares across a wide range of ETFs. Robinhood offers recurring buys and fractional shares from one dollar. Schwab supports recurring purchases but its fractional-share program covers S&P 500 stocks, not all ETFs, so exact-dollar ETF automation is limited. Vanguard's automatic investing is strongest for its own mutual funds rather than ETFs across the market. Broker features change, so verify current terms on each broker's own site.
Yes. Most major brokers let you schedule recurring ETF purchases (for example, every payday or once a month) that run without you placing each trade. The feature that makes it work cleanly is fractional shares: without them, a recurring deposit can only buy whole shares, so leftover cash sits uninvested. Brokers that combine recurring buys with fractional ETF shares, such as M1 Finance, Fidelity, and Robinhood, let you invest a full fixed amount automatically. This is a common way to dollar-cost average into a portfolio.
Vanguard's automatic-investment feature has historically been built around its own mutual funds, which have long supported scheduled purchases in exact dollar amounts. For ETFs, Vanguard's fractional-share purchases are limited to Vanguard ETFs, so building a hands-off, exact-dollar plan across ETFs from other providers is more limited than at brokers like M1, Fidelity, or Robinhood. If you specifically want automatic investing and prefer Vanguard funds, their mutual funds may fit the goal better than their ETFs. Verify current functionality on Vanguard's site, as brokerage features change.
Not strictly, but they make it work far better. Without fractional shares, a recurring purchase can only buy whole shares of an ETF, so a 200 dollar deposit into a fund trading at 150 dollars buys one share and leaves 50 dollars in cash until it accumulates enough for the next whole share. Fractional shares let the full deposit go to work every time, which is the point of an automatic, dollar-cost-averaging plan. That is why brokers built for automation, such as M1 Finance, default to fractional shares.
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