Which investments should go in which type of account?

This is called asset location, and it can quietly boost after-tax returns. The rule of thumb: put tax-inefficient assets — taxable bonds, REITs, and actively traded funds that throw off interest and short-term gains — inside tax-sheltered accounts like a 401(k) or traditional IRA. Put your highest-growth assets, like stock index funds, in a Roth IRA where decades of gains come out tax-free. Hold tax-efficient broad stock index and total-market ETFs in your taxable brokerage, since they generate little taxable income and qualify for low long-term capital-gains rates. International stock funds often fit taxable too, because you can claim the foreign tax credit. The point isn't to change your overall allocation — it's to place each piece where the IRS takes the smallest bite. Treat all your accounts as one portfolio when deciding.