The easy thing to do when you are investing is to look at how much your portfolio is going up or down.

But that’s not what’s really important. What’s important is how much of your investment portfolio, you get to keep and how much goes to Federal, state and local taxing authorities.

For example, an IRA defers taxes until you take the money out. Under current law, once an investor turns 70 1/2, he has to start taking money out of the IRA. This is called a required minimum distribution.

When an investor takes money out of the IRA, he has to pay ordinary income taxes on the withdrawal. This can be a third in combined taxes or even more.

If he has a Roth IRA and is over $59 1/2 and the Roth has been open five years, he probably won’t owe any taxes.

If he has a regular taxable account — no retirement savings vehicles — and owns mutual funds, he may owe taxes even if he doesn’t do any trading himself for the year. Mutual funds must distribute most of their income each year to avoid saddling their shareholders with double taxation.

In a strong stock market, like the market this year, gains accumulate in actively managed mutual funds and taxable distributions can be quite high.

Investors need to be aware not just of their investment returns but of how much of those gains they will keep. That makes a huge difference in long-term financial well being.