Thank you! So does that mean if the Traditional IRA suffers a loss, then I get a positive balance, but if the Traditional IRA makes a profit (e.g. instead of $5981, it ended up with $6081 when the market closes), I actually have to pay tax on that extra $81? Is this how the basis works - even if the contribution was after-tax, but depending on whether the investment turned into a profit, there may be taxable amount at Roth Conversion time?
