What happened

Robotic vacuum specialist iRobot (NASDAQ:IRBT) beat the market last month, rising 16% compared to a 6% increase in the S&P 500, according to data provided by S&P Global Market Intelligence.

^SPX Chart

^SPX data by YCharts.

The spike added to the stomach-churning volatility that shareholders have been experiencing lately. iRobot's stock has been up as much as 70% -- and down by as much as 10% -- in just the past 52 weeks.

So what

January's rally reflected rising optimism that iRobot had a solid holiday sales quarter. After all, Amazon.com announced in late December that robotic vacuums were among its best-selling items during the holiday rush, and that bodes well for the industry leader. (iRobot owns roughly 64% of the market for premium vacuum devices.)

A man reclines on a white couch while a robotic vacuum cleans the floor.

Image source: Getty Images.

Now what

At its latest quarterly check in in late October, iRobot raised its outlook after sales spiked 22% in the third quarter. CEO Colin Angle and his executive team believe revenue will now stop at $875 million at the midpoint of guidance.

Investors will find out on Feb. 7 whether the company hit that aggressive target or instead had to settle for something lower as competition ate away at its dominant market share in the robotic vacuum industry.