While stocks got off to a generally upbeat beginning to the week Monday, a few laggards managed to post big losses despite a broader bullish sentiment. The gains were modest; it'd be nice to say that the S&P 500 Index (^GSPC 1.20%) wasn't setting any records, but it actually was: its 3 point gain today, although just a 0.2% uptick, sent the index to 1,695, an all-time closing high. 

Yahoo! (NASDAQ: YHOO) shares had the most difficulty today, slumping 4.3% as the company lost three members of its board of directors and a high-ranking executive, all in a day's time. No immediate successor is known as media head Mickie Rosen steps down, according to Kara Swisher at AllThingsD. One of the board members, activist investor Daniel Loeb, is also the CEO of the hedge fund Third Point, and his departure comes as Third Point liquidates about $1.2 billion in Yahoo! stock.

Advanced Micro Devices (AMD 2.44%) shares continued a precipitous drop Monday that began with Friday's 13.2% slump. Slipping another 3.2%, investors continued a sell-off that began in earnest after the chipmaker reported quarterly earnings that sparked several high-profile analyst downgrades. While today's fall may be to some extent a continuation of Friday's collapse, AMD also saw heightened competition Monday. Intel vowed to start making low-power chips for servers on Monday, as Intel moves more consciously into the server and mobile markets AMD already competes in. 

Finally, Sprint (S), which only recently dropped the "Nextel" part from its trading name, fell 2.5% as it continues a sell-off that began last week. After a 22% rally on the heels of Japan's SoftBank acquisition of the company, shares began to slip last Tuesday, as a slump began that's sheared nearly 12% off Sprint's market cap. Investors will get a better clue about trends at the company when it announced quarterly results next Tuesday, July 30.