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 daily deal site Groupon (Nasdaq: GRPN) were clipped by as much as 10% today following the end of the insider lock-up period.

So what: Today marked the end of the 180-day lock-up period, which allows certain corporate insiders to sell shares of the company. The remaining 93% of shares held back since the IPO will now be available for trading, but insider sales could add continued downside pressure on the already weakened stock.

Now what: What, you actually thought you could go a week without drama from Groupon? Groupon can't catch a break thanks to its multiple accounting snafus and the small barrier to entry that has allowed for increased competition from Microsoft's MSN Offers; Living Social, which has financial backing from; and now Google, which has integrated daily deals into its Maps platform. Groupon shareholders could get lucky and insiders may not sell many of their shares, but when has anything gone investors' way with this stock? Now we just watch and wait for those SEC filings to roll in.

Craving more input? Start by adding Groupon to your free and personalized watchlist so you can keep up on the latest news with the company.