Marcus Invest joins a growing list of robo advisers (see “The Right Robo Adviser for You,” Feb.). The low-cost digital platform invests in portfolios of exchange-traded funds based on models developed by Goldman Sachs investment-strategy experts. Like other robos, Marcus Invest automatically rebalances portfolios periodically to align with your goals. The minimum investment is $1,000. You’ll pay a 0.35% advisory fee, deducted quarterly. Invest is part of a suite of financial services offered through the Marcus app or on the website. Besides Invest, Marcus offers a no-fee, no-minimum online savings account that yields 0.5% and a variety of personal loans. A checking account is in the works.