What happened

Shares of customer service platform Zendesk (ZEN) moved about 13.8% higher in January, according to data provided by S&P Global Market Intelligence. The stock likely benefited from several catalysts during the month.

First and foremost, January was generally an optimistic month for most stocks. The S&P 500, for instance, rose about 6% during the period. But Zendesk's bullish run in 2017 and anticipation of the company's fourth-quarter earnings release could have been key drivers, too.

A chart showing a stock price moving higher

Image source: Getty Images.

So what

2017 was a big year for Zendesk; its stock rose about 60% as the company repeatedly outperformed investor and analyst expectations. The stock's rise in January could have simply represented growing bullishness as investors digested Zendesk's solid underlying results in 2017.

Another possible catalyst for Zendesk stock in 2017 could have reflected investors anticipating another solid earnings report of quarterly results in February. Sure enough, Zendesk did report better-than-expected fourth-quarter results.

Now what

In February, Zendesk's strong fourth-quarter results have helped the stock remain surprisingly resilient amid a market sell-off. Zendesk shares have fallen just over 1% month to date. The S&P 500 is down about 10% during this same period.

In 2018, Zendesk expects its strong business growth to continue, with management guiding for full-year revenue to climb about 29% to 31% year over year.