Based upon not charging any fees for their service, it looks like Wealthfront is the cheapest robo advisors today.
Surprisingly, despite their low ETF fees, Vanguard didn’t come out the winner at any deposit amount. In fact, they turned out to be one of the most expensive of the six. While Vanguard does allow you to speak to an advisor, I’m not sure what value they add since they won’t give advice on funds outside of their service. Is Vanguard’s service worth five basis points more than the competition? That remains to be seen. Vanguard is also somewhat limited for the beginning investor since they require a minimum of $50,000 to invest.
With any of the robo advisors, understand the real annual fee you pay. Which provider has the better allocation for higher future returns? Who knows — that’s a crapshoot.
While you cannot control what the market will do, you can control taxes and fees. Make sure you are getting the best service available, at the lowest possible fee. That’s not to say you should automatically go with the lowest cost robo advisor, but the one that best meets your investing objectives.