Exactly. If you got a bonus and you're deciding whether to invest it into an IRA or into a taxable brokerage, you pick the IRA because it has tax advantages. Likewise, if you consider a Roth IRA to be a form of emergency fund, then putting your efund into a Roth IRA just avoids losing that space.

However, you shouldn't be investing your emergency fund regardless of tax treatment, so funding and investing in a Roth IRA with money you're not planning to use for investing just opens you up to more risk.

Likewise, time in the market beats timing the market, so don't hold back money to invest on Jan. 1. I personally invest an even amount every month and have it automated through my brokerage, and it works really well for me.