When do you normally invest new money? Right after a paycheck? On the first of the month? I would say you should do whatever you normally do, and don't pay attention to what the market is doing right now. If you normally invest on the first of the month, then I'd say wait until Jan 1 and direct your money into your IRA. Continue directing into your IRA until you have maxed it out for the year, then redirect subsequent money to your taxable account. On the other hand, if you normally invest ASAP following a paycheck, then I'd stick with that pattern as well. Invest in your taxable account now, and then start investing in your IRA following your first January paycheck.
If you don't have a routine habit, then maybe now is a good time to establish one.