RetireBy90
Thinks s/he gets paid by the post
I can do a one time $6k but that means I will have to withdraw from my taxable account.
VTSAX is a taxable account at Vanguard.
FZROX is a Roth IRA at Fidelity.
Again, I understand you will incur cap gains if you withdraw from taxable account. So your choice. I don’t see any significant difference.
If you do the withdraw from your taxable account you will have to pay short term cap gains of 22%. However you will get any gains in 2022 tax free.
If you do monthly $500 then no cap gains as VSTAX can continue to grow, with tax hit delayed and possibly be at a lower rate.