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 Examworks Group, (NYSE:EXAM) are trading nearly 12% lower today after the company announced the offering of 3.1 million shares -- about 8% of all shares outstanding -- by some of its major shareholders, at a price of $33.90 per share.

So what: Examworks itself will get nothing from this offering, but more than $100 million will flow to several major shareholders, who also have a 30-day option to sell nearly 500,000 additional shares. The largest individual block of shares being sold is held by current Executive Chairman and former co-CEO Richard E. Perlman, who can divest roughly half of his 2.3 million shares with the exercise of options. Other major sellers include board member William A. Shutzer (who can sell roughly half of his 1.2 million shares), and CEO James K. Price, who can sell a bit less than half of his 2 million shares).

Now what: Investors don't like to see two of the most important people on their company's leadership team bailing out of half of their stakes, and it's not as though either Perlman or Price suddenly gained a windfall of shares -- their 2013 stock-based compensation bonuses work out to less than 3% apiece of their total currently owned shares. Examworks is hardly floundering, either -- its revenue has grown fourfold since the end of 2010, and free cash flow was roughly 150% higher during the same period. This large sale by so many company insiders, after a period of impressive growth, should force investors to wonder whether these executives are getting out while the getting's good.

Alex Planes has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.