n the event you hold a mutual fund in an account that is not sheltered from taxes – that's, outdoors a 401(k), IRA or comparable strategy – you will most likely owe some taxes around the fund each year, even when you do not sell a single share. That is simply because as a fund owner, you also personal all of the stocks, bonds or other holdings within the fund's portfolio.
So for the stock funds, you will need to spend taxes on stocks your fund manager sold that year, also as around the dividends that the fund collected. For the bond funds, you will need to spend ordinary earnings taxes on interest. (Some bond funds, nevertheless, like municipal bond funds, escape taxation.)