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.

Despite the broad-based S&P 500 (SNPINDEX:^GSPC) cracking the 1,800 mark for the first time ever intraday, traders took the opportunity Monday to take some profits and pushed the index lower by session's end.

The only bit of economic data even remotely influencing the markets today came from the National Association of Home Builders, which reported a November reading of 54 for builders confidence. That was in-line with October and generally mixed with economists' forecasts. With interest rates dropping back down to a four-month low it's a bit worrisome that optimism hasn't improved among homebuilders, which could be another reason why the market is moving lower today.

By day's end, the S&P 500 finished in the red by 6.65 points (-0.37%) to close at 1,791.53.

No company stood atop the mountain with a bigger grin today than 3-D printer manufacturer Voxeljet (NYSE:VJET) which added 15.9% to close at $68.37. This after pricing its IPO just one month ago today at the low end of its range, $13 -- that's one heck of a one-month return! Today's jump is a continuation rise fueled by positive commentary from Piper Jaffray on Friday, as well as a very strong earnings report on Thursday highlighted by a 77% increase in revenue and a modest profit (compared to a small loss in the year before). It's quite possible that emotions have gotten the better of investors at this point, but it's plain as day that 3-D printing has the potential to reshape the manufacturing and industrial sectors over the next decade.

Also pushing to the upside in a big way today was clinical-stage biopharmaceutical company Synta Pharmaceuticals (NASDAQ:SNTA.DL) which advanced 15.2% after completing a secondary share offering and following an SEC filing that one of its directors, Bruce Kovner, purchased a monstrous 5 million shares of the company for $18.8 million. Synta's share offering helped raise $60.4 million pre-tax for the company to use in developing its pipeline, conducting clinical trials, and potentially marketing any therapies that are approved by the Food and Drug Administration. The real news here, though, is the massive insider buy -- and it should be noted that a separate director also bought $562,000 worth of Synta common stock. Directors often have a close understanding of the company's they act as advisers for, so this move is viewed by current shareholders as incredibly bullish, especially with Synta's lead drug, ganetespib, currently in late-stage trials as a second-line treatment for non-small cell lung cancer.

Finally, recent IPO The Container Store (NYSE:TCS)added 12.2% despite a lack of company-specific news. The move does, however, come shortly after research firm Stifel Nicolaus initiated coverage on the storage company with a buy rating and favorable $43 price targe. Despite Stifel's bullishness, I'm not nearly as excited. I would suggest waiting for The Container Store to (for lack of a better phrase) "deliver the goods" before you bet big on a company that looks only modestly profitable. The IPO market is incredibly saturated at the moment; I'd caution that it could be one of the next bubbles to burst.