Falling slightly, the S&P 500 Index (^GSPC -0.22%) reacted to unexpectedly declining consumer confidence numbers as it headed into the weekend. Also declining were a slew of the index's components, though few fell more swiftly than today's three worst.

Intuitive Surgical (ISRG -0.41%) stock, already in a troublesome slump, fell a further 6.2% today, to top out as the worst-performing S&P component. When it rains it pours, and yesterday's nearly 4% losses steepened today, as a major OB/GYN group president discouraged the use of robots in hysterectomies. Invoking a lack of data to prove the utility of robots in such procedures, Dr. James Breeden noted that robotic hysterectomies are also far more expensive than other current methods. Overall, a pretty convincing argument against Intuitive's breadwinning products.

Headaches over talent retention made news as shares of Abbott Laboratories (ABT -0.59%) stumbled today; it fell 2.9% after filing a lawsuit against a former employee who the company says recruited several others away after joining Boston Scientific at the beginning of this year. While it may seem like small potatoes, protecting company secrets and proprietary medical knowledge is vital in a multibillion-dollar, ultra-competitive space like medical devices.

The last of the day's laggards, online auction site eBay (EBAY 1.01%) saw its stock fall 2.7%. Its PayPal business unit acquired a mobile app developer by the name of Duff Research on Wednesday for an undisclosed amount. With the shift to mobile devices perhaps the most visible and opportunity-laden paradigm shift going on in technology today, it's great that eBay is embracing mobile. At the same time, with abundant competition from all over the globe, investors would like PayPal to already be at the point where it didn't have to buy up-and-coming companies for their expertise.