Stock futures lost ground on Friday as a brief boost that followed the March non-farm payrolls report faded.

Both the S&P 500 and Dow industrial stock index futures slipped into negative territory, suggesting Wall Street could open mixed.

March U.S. payrolls fell by 663,000, government data showed. Initially, some analysts had said the data suggested the market had possibly seen the worst but that enthusiasm soon dissipated.

S&P 500 futures fell 3.90 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures shed 10 points, and Nasdaq 100 futures added 3.50 points.

(Reporting by Ellis Mnyandu; Editing by James Dalgleish)