I have no idea. You might lose money. It all depends on the type of fund and what the market does in the next year. Here are the returns for Vanguard funds:
https://investor.vanguard.com/mutual...th-end-returns
As you can see, the returns are all over the place, and many of them are negative.
What is your goal? Are you saving for retirement? Kid's education? Saving for down payment on a house?
A good rule of thumb is don't invest in stocks if you will need the money in the next five years.
If you want safety, a CD or Treasury bond is the way to go, but the interest rates are low.
Do you have debt? Paying off consumer debt (credit cards, student loans, car loan, boat loan) or mortgage debt gives you a safe, guaranteed return equal to the interest rate on the debt. IMO, you should not even consider the stock market if you have consumer debt. Paying off consumer debt is a far better use of your money.