Just because we're not knee-deep in earnings reports yet doesn't exactly mean that everyone is taking an earnings hiatus. During the New Year's shortened week, a handful of companies reported their quarterly results, with three in particular catching my attention for their healthy surprises to the upside.

Although an earnings beat isn't grounds to buy a stock, it can often signal continued strength in a sector or in that stock for months to come. Here are three companies that blew past Wall Street's estimates last week that could be worth keeping an eye on.

Company

Consensus EPS

Reported EPS

Surprise %

Xyratex (Nasdaq: XRTX) $0.33 $0.73 121%
Mosaic (NYSE: MOS) $1.30 $1.40 8%
Greenbrier  (NYSE: GBX) $0.36 $0.48 33%

Source: Yahoo! Finance.

Xyratex
You might be looking at that 121% earnings beat and thinking that Xyratex rocketed higher following that report. If so, you'd be sorely mistaken.

Underlying the huge earnings beat was another quarter of revenue declines highlighted by NetApp (Nasdaq: NTAP) cutting back on its needs for Xyratex's storage products. The real highlight of this report was the resurgence in Xyratex's gross margin -- specifically in its network storage services division. For the fourth quarter, gross margin shot to 17.7% from just 13.3% in the year-ago period and up 50 basis points from the third quarter. It's no wonder Xyratex's earnings were so strong based on these gross margin figures. Although it's tough to predict whether Xyratex will move higher from here with little revenue momentum, it's clear that its core customers are still using its products -- and if gross margins continue to tick higher, so will Xyratex.

Mosaic
Mosaic and the entire fertilizer sector have been under constant pressure for months now. The reason is that many analysts believe it's going to be tough if not impossible for fertilizer companies to match the record demand for their products in 2011 moving forward. To some extent, they're right.

On Wednesday, Mosaic reported that its second-quarter earnings tumbled 39% over the year-ago period -- although that year-ago report was aided by a one-time sale of its Fosterfil business. Still, these results handily beat Wall Street's forecasts, and the company went on to say during its conference call that it expects record phosphate and potash shipments in 2012. With this news and Mosaic's assertion that prices have indeed bottomed out, it could mean that good times are once again ready to return to the fertilizer stocks.

Greenbrier
Unlike Xyratex and Mosaic, there was no doubting Greenbrier when the company reported first-quarter results on Friday. The railroad-equipment supplier expects significantly higher sales and profits in 2012 as demand for the energy sector really ramps up. Greenbrier didn't just crush estimates by $0.12; it also reversed a year-ago quarterly loss of $0.11 on a doubling in revenue.

The strong results from Greenbrier really shouldn't come as a surprise to anyone, least of all me. I've been a railroad and railroad equipment bull since last year and think the rally could continue throughout 2012. With railcar producer FreightCar America's (Nasdaq: RAIL) sales surging in the third quarter and surpassing analyst estimates by about 30% in November, it signaled open season for the railroad-equipment suppliers to join the party. Greenbrier looks like a good bet to outperform in 2012.

Foolish roundup
Three companies with three impressive earnings beats. I've given my two cents on what's next for each of them, now it's your turn to sound off. Share your thoughts in the comments section below, and consider adding these stocks to your free and personalized watchlist to keep up on the latest news with each company.