Put $5,500 in a 2017 Betterment traditional IRA right now. As in right now. Put the other $4,500 into a 2018 Betterment Roth IRA and use it as an emergency fund. But do it today. Do it now. You can pull out the original $4,500 in an emergency while still gaining a good ROI when it sits.
Edit: You’ll also get a higher refund on taxes this year (if you haven’t filed yet) with your traditional IRA contribution. Here’s a link to a Roth IRA as an emergency fund.