The Federal Reserve meeting next week is not on the minds of as many people as when it met in September, but its decision to do nothing last month is providing the fuel for more share gains in Apple and Facebook, which report results next week.

Facebook is only slightly off an all-time high, and Apple has recovered somewhat from losses earlier in the year after investors have poured money back into stocks, bringing the S&P to successive records that some say may not be supported by corporate results.

The numbers from Facebook (FB.O) and Apple (AAPL.O) are among those that will be closely watched - and investors say at their current levels, the margin for error is slim.

Nearly half of the S&P 500 companies have reported their third-quarter results so far, and 69 percent have beaten Thomson Reuters I/B/E/S estimates. The technology sector has led the way, beating expectations 84 percent of the time. The most recent companies to do so were Amazon.com (AMZN.O) and Microsoft (MSFT.O), whose results led the S&P to close at an all-time high of 1,759.79 on Friday.

Companies already stretched to high price-to-earnings multiples, like Facebook, will have to outpace expectations to keep investors buying."There is not a lot of room for error, especially with these names with a lot of momentum behind them. You have to beat the numbers pretty handily," said Daniel Morgan, vice president and senior portfolio manager at Synovus Trust Company in Atlanta, who focuses on tech stocks.

That's where the Fed comes in. Some of the riskier names and high-dividend payers had pulled back in the late summer, anticipating the Fed would begin reducing monthly bond purchases beginning at its September meeting. But that didn't happen - and since then, stocks have been unimpeded, save for the 16-day government shutdown that didn't scare too many people.

The Federal Reserve will hold its October meeting on Tuesday and Wednesday this week. But earnings will overshadow the central bank, as it is expected to maintain its current policy, in part because of the economic hit that resulted from the shutdown.

"So far, this earnings season has been pretty balanced and on the positive side," said Paul Mangus, head of equity strategy and research for Wells Fargo Private Bank in Charlotte, N.C. "If that continues into next week, and we're not expecting anything surprising out of the Fed, it could continue to support markets on current levels."

Mangus noted that expectations for the third quarter were low, so beating earnings estimates is not a particularly bold sign of strength. Many companies were able to create earnings without actual revenue growth, so 46 percent of results so far revealed lower-than-expected revenue growth."The sales numbers have been anemic. We're pretty flat in terms of across the board revenue," Mangus said.For the past week, the Dow was up 1.1 percent, the S&P rose 0.9 percent and the Nasdaq gained 0.7 percent.