What happened

Shares of Appian (NASDAQ:APPN) soared on Monday. There was no company-specific news driving the rally, but the broader stock market enjoyed a strong day. Appian stock was up about 11.8% at 3:30 p.m. EST today.

So what

Shares of Appian had been trending downward ever since early September of last year. A secondary offering of common stock sent shares lower, and somewhat weak guidance in October didn't help the situation.

The software-as-a-service company said it expected fourth-quarter revenue between $69.1 million and $70.1 million, compared with the average analyst estimate of $70.1 million. Non-GAAP (adjusted) EPS is expected to be a loss of $0.14 or $0.15, worse than the $0.11 loss analysts were expecting.

A chart with a rising arrow.

Image source: Getty Images.

Now what

The volatility being experienced by Appian stock may have something to do with the valuation. After Monday's surge, the company is valued at about $3.3 billion, putting the price-to-sales ratio over 20, based on Appian's guidance. Revenue is expected to grow by 33% to 34% this year, which is quite a bit slower than other high-profile software-as-a-service stocks.

A big rally is always exciting for shareholders, but Appian stock remains down nearly 20% since peaking late last year.