Set up automatic investing, broker by broker

Fidelity

Fidelity: FSKAX, FTIHX, FXNAX

All three are Fidelity's own index mutual funds, and Fidelity can buy all three for you on a schedule, in a brokerage account or an IRA [1].

1. Open the account and link your bank.
2. Go to Trade, then Recurring Investment. Pick Mutual Funds and the account.
3. Add FSKAX, FTIHX and FXNAX, with a dollar amount for each in your plan's percentages.
4. Pick how often (weekly, every 2 weeks or monthly) and a start day, the day after payday.
5. Turn on paying from your linked bank, so the money comes straight from checking. Preview, then Confirm.

$10 minimum per fund, no fee for the feature. If the menu has moved, search Fidelity's site for "recurring investment".

Charles Schwab

Schwab: SWTSX, SWISX, SCHZ

Schwab only automates mutual funds, so SWTSX and SWISX buy themselves and SCHZ, an ETF, is a quick buy by hand [2].

1. Open the account and link your bank.
2. Buy a little SWTSX and SWISX by hand first. Schwab only lets you automate a fund you already own.
3. Go to Trade, then Automatic Investing, pick the account, and click Enroll next to each fund. Set the amount, how often and the day, then Continue and Submit.
4. Set a recurring deposit from your bank a day or two before that date.
5. Once a month, buy SCHZ with what's left for bonds.

SWISX skips emerging markets. It's fine, and it's what Schwab automates. If the menu has moved, search Schwab's site for "automatic investing".

Vanguard

Vanguard: VTI, VXUS, BND

Vanguard now does recurring buys of its own ETFs, in dollars, from $1 [3]. Vanguard doesn't publish click-by-click steps, so these are the general shape.

1. Open the account and link your bank.
2. Find Recurring investing, under automating your investing.
3. Pick the account, add VTI, VXUS and BND with a dollar amount for each, and set how often and the start day.

If your account doesn't offer it for ETFs yet, the mutual fund versions (VTSAX, VTIAX, VBTLX) automate the same way, with a $3,000 first buy each.

Robinhood

Robinhood: VTI, VXUS, BND

Robinhood buys any of the three on a schedule, in dollars, in a regular account or an IRA [4]. You set one recurring buy per fund.

1. Open the account and link your bank.
2. Go to VTI's page, tap Trade, then Buy, and enter a dollar amount.
3. Tap the order type at the top right, then Recurring investment. Pick how often (every market day, weekly, every 2 weeks or monthly) and pay from your bank. Review and submit.
4. Do the same for VXUS and BND.
5. For an IRA, schedule the deposit too: Account, Menu, Transfers, Recurring deposits, pick the IRA, then New IRA contribution.

Buys from your bank wait for the transfer, up to 5 business days. Fractional shares can't move to another broker, so leaving means selling.

M1

M1: one Pie of VTI, VXUS, BND

M1 is built for this. You set the percentages once, and every deposit buys in that split on its own [5].

1. Open the account. The first deposit is $100, or $500 for an IRA.
2. Go to Invest, Portfolio, Edit, Add Slice, and add VTI, VXUS and BND at your plan's percentages.
3. Go to Move Money, Recurring Transfer. Set the amount, from your bank, how often and the day.
4. Check that auto-invest is on, under Automation. It's on by default and buys once you have $25 in cash.

M1 charges $3 a month unless you have $10,000 or more there.

After it's set up

Turn on dividend reinvestment, turn off price alerts, and put a reminder on your calendar for once a year. That's it (have I said this enough?). What to do when the market drops.