Large-cap tech stocks overall have performed very well recently. Consider how the tech-concentrated NASDAQ 100 index handily outperformed the S&P 500 in the past twelve months, soaring 17%, or about seven percentage points higher than the 10% gain the S&P 500 saw during the same period.

^NDX Chart

^NDX data by YCharts

Two major contributors to the outperformance of the NASDAQ 100 are Apple (NASDAQ:AAPL) and Facebook (NASDAQ:FB). While the two stocks are part of both indices, they account for a much larger portion of the NASDAQ 100 than the S&P 500. In the past twelve months, Apple and Facebook are up an astounding 43.6% and 32.3%, respectively.

Given their impressive gains and a pricey market in general, the stakes will be high for these tech giants when they report earnings this month. If you plan to tune into their reports, mark your calendar for 5:00 p.m. ET on Jan. 27th (Apple earnings) and 5:00 p.m. ET on Jan. 28th (Facebook earnings). 

While will be covering both stocks closely before and after the announcement, here's an early look at investor expectations and key items to watch.

Fueled by what is expected to be record iPhone sales, analysts have high hopes for Apple's first fiscal quarter, which coincides with the fourth calendar quarter. The consensus estimate is for record revenue and EPS of $66.4 billion and $2.54, up 15.3% and 22.7% from the year-ago quarter, respectively.

Image source: Apple

The key metric for investors to watch is undoubtedly iPhone sales. The 4.7 and 5.5-inch iPhone 6 and 6 Plus put Apple right smack in the middle of a proven market for smartphones larger than the 4-inch iPhone 5s. Analysts are expecting Apple to report sales of about 63 million units during Q1, up about 23.5% from the 51 million units sold in the year-ago quarter.

It appears Apple will have no problem meeting expectations. But downside surprises -- even for Apple -- are always possible and may result in temporary volatility for the shares.

Analysts expect a record quarter from Facebook as well. Consensus estimates for revenue and EPS sit at $3.78 billion and $0.48, up 46.5% and 54.8% from the year-ago quarter, respectively.

One of the key overarching stories for Facebook remains the same: revenue growth. The social network's topline growth since it went public in May 2012 has exceeded even the most optimistic initial estimates.

Facebook's year-over-year revenue growth rates recently stopped a streak of sequential hikes, but the rates themselves are still very impressive.

FB Revenue (Quarterly YoY Growth) Chart

FB Revenue (Quarterly YoY Growth) data by YCharts

Investors looking to get a pulse check on Facebook when the company reports earnings should look for revenue growth of 46% or higher. With a price-to-earnings multiple of 73, growth is key to justifying the current stock price. Beyond the revenue figure itself, investors should look for updates from management on growth expectations going forward to get a more accurate idea of the company's trajectory.

Stay tuned at The Motley Fool for more detailed earnings previews on Apple, Facebook, and more as earnings season kicks off.