The S&P 500 Index (SPX) has battled back from its brutal month-long sell-off, but it seems that traders aren't exactly confident in the market's fledgling rebound. According to data from the Chicago Board Options Exchange (CBOE), options players are betting on additional turbulence by purchasing calls on the CBOE Market Volatility Index (VIX).

During the past five sessions, speculators on the exchange have scooped up 142,544 calls on the VIX, along with 126,391 puts. In other words, 1.13 calls have been purchased for every put on the VIX, which is meant to reflect investors' expectations for the SPX's near-term price action.

The CBOE Market Volatility Index (VIX) is up nearly 10% this afternoon, buoyed by a down day in the U.S. equities market. Today's jump in the VIX likely comes as no surprise to option speculators, who have recently been loading up on VIX call options.

During the past five days, option traders on the Chicago Board Options Exchange (CBOE) have bought to open 177,441 calls on the VIX, compared to just 74,637 puts. In other words, about 2.38 times more calls than puts have been purchased on the so-called "fear index" during the past week.

Standard & Poor's is performing some end-of-year cleanup on its benchmark index, the S&P 500 Index (SPX). My colleague Mark Fightmaster reported earlier that Visa (V) is set to replace Ciena Corp. (CIEN) on the widely watched market barometer, but that's not the only SPX development hitting Wall Street today. In fact, struggling insurance issue MBIA Inc. (MBI) is preparing to take its leave from the venerable index.

In a press release late Friday, Standard & Poor's explained that MBIA "currently ranks 500th in the index and is no longer representative of the S&P 500 index market cap space." The beaten-down insurance company will be replaced by Mead Johnson Nutrition (MJN), which is in the process of being spun off by Bristol-Myers Squibb (BMY).

Late Friday, Standard & Poor's (S&P) announced that it will add four new companies to the S&P 500 Index (SPX), including credit card company Visa (V). Visa will replace telecom equipment company Ciena (CIEN). S&P stated that all the companies moving to the index have market caps above $5 billion, which makes them more representative of the market-cap range.

This morning, analysts are reacting to the news, setting up Visa for a bit of a news-related Monday rally. RW Baird upgraded Visa to outperform from neutral and upped its target price from $88 to $100, noting that it expects growth to reaccelerate growth over the next couple quarter, "along with annual earnings-per-share growth of more than 20 percent over the next couple years." Baird also believes that improving retail sales will help Visa. In addition, William Blair upped its estimate on Visa in order to reflect "an improved volume outlook."

Auto parts company O'Reilly Automotive, Inc. (NASDAQ: ORLY- option chain) is one of the newest additions to the S&P 500 Index (SPX). Standard & Poor's announced late Thursday that ORLY will join the venerable index after the close of trading on March 26, where it will replace Noble Corp. (NYSE: NE).

The news caps off a pretty good week for ORLY; on Wednesday, Robert W. Baird initiated coverage of the stock with an "outperform" rating, and the equity tagged a new 52-week high of $36.17 in Thursday's session.

Just last week, Hormel Foods Corporation (NYSE: HRL) surprised investors with stronger-than-expected first-quarter earnings. Sales during the period were boosted by healthy demand for the company's recession-friendly canned ham-like product, Spam. Today, it seems that Standard & Poor's is revealing its own soft spot for potted meat, announcing that HRL will join its storied S&P 500 Index as of the close of trading on March 3.

Hormel will replace American Capital Ltd. (NASDAQ: ACAS) in the closely watched broad-market index. The latter stock has given up nearly 96% of its value during the past year, and it's extending those losses today with a plunge of more than 16%.

With the end of the year fast approaching, it's time to start putting together "best of" and "worst of" lists for 2008. This entry is a little bit of both, but it's admittedly heavy on the "worst of." Among the current members of the S&P 500 Index (SPX), just 11 were sitting on a year-to-date gain as of the close of trading on Monday, November 24. Since Big Lots (NYSE: BIG) is unchanged, that means we have a whopping 488 securities sitting on a loss for the year.

Let's start with the bad news first. Among the worst-performing stocks on the SPX, the six top spots are claimed by stocks in the Insurance and Real Estate sectors. General Growth Properties (NYSE: GGP) has the dubious honor of dropping nearly 98% on the year, and -- not surprisingly -- American International Group (NYSE: AIG) isn't far behind.