Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Barrett Business Services (BBSI 0.38%) fell 10% today after the company announced fourth quarter results.

So what: Net revenue was up 27% to around $144.5 million and adjusted net income rose 50% to $8.7 million, or $1.16 per share. That was in line with previously released estimates but guidance was below expectations.

Management expects first-quarter revenue to be up at least 24% to $735 million to $755 million and a loss per share of $0.45 to $0.50. Revenue is below the current analyst estimate of $761.2 million in revenue and a $0.48-per-share loss.

Now what: This is typically a slow quarter, so I wouldn't be too alarmed with the guidance figures. More important will be how management sees the year unfolding in the second half of the year. I'm not a buyer given the forward P/E ratio over 20, but if shares continue to fall slightly, there could be nice value given the company's growth rate.