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.

For a second consecutive day the broad-based S&P 500 (SNPINDEX:^GSPC) waffled within a tight trading range as the market waits impatiently for the next round of economic data to hit the tape.

The only somewhat interesting bit of data was October's wholesale inventory increase of 1.4%, which was a bit higher than expected, but not shocking considering that we're headed into the holiday season and consumer spending hasn't lived up to expectations in recent months.

The big news of late, and the likely reason that the S&P 500 ended the day modestly lower, has been the rapidly improving economic picture (e.g., U.S. GDP growth and dropping unemployment) which suggests the Federal Reserve's will begin drawing down its monthly bond-buying stimulus sooner rather than later.

The S&P 500 ended Tuesday trading to the downside by 5.75 points (-0.32%) to close at 1,802.62, ending its two-day streak of gains.

Leading all stocks to the upside today was small-cap biopharmaceutical company Enanta Pharmaceuticals (NASDAQ:ENTA) which plowed higher by 28.6% after AbbVie (NYSE:ABBV) reported positive data from its second of six phase 3 studies in treating hepatitis C. This particular study, known as the Sapphire-II trial, tested AbbVie's direct-acting antiviral combo, of which one compound (ABT-450) was developed by Enanta, on previously treated hepatitis C patients. The results demonstrated a sustained virologic response after 12 weeks in 96% of genotype 1 patients. These results are truly incredible, not only for the dramatic increase in SVR over existing treatments, but because AbbVie's DAA combo isn't given with interferon which has the propensity to cause flu-like symptoms in patients. Not to mention that genotype 1 is by far the most common form of the disease and will have the broadest treatment appeal. It's looking good that AbbVie's combo drug will be the blockbuster that Mr. Market expects, which would be fantastic news for Enanta over the long run.

Sticking within the biopharmaceutical sector, small-cap Relypsa (NASDAQ:RLYP) shot higher by 16.6% after research firm Stifel Nicolaus initiated coverage on the company with a buy rating and a $25 price target, implying 25% upside from yesterday's close. Stifel noted that the company's late-stage hyperkalemia drug, patiromer, has demonstrated encouraging results in clinical studies and should present chronic kidney disease sufferers with a long-term solution to potassium reduction that diet and existing therapies do not adequately provide. But I still suggest not counting your chickens before they're hatched, with Relypsa stock now having nearly doubled since its IPO less than four weeks ago.

Finally, technology solutions licenser Rambus (NASDAQ:RMBS) advanced 12.3% after announcing a licensing deal with Micron Technology (NASDAQ:MU) that ended all patent disputes between the two companies. According to terms of the deal, Micron receives the right to use Rambus' patented technologies in the development of select integrated circuits, and in return Rambus will receive a $10 million quarterly royalty payment for the next seven years, totaling $280 million overall. It's definitely important to see Rambus put these issues in the rearview mirror, but I'm still not particularly enticed by the company's ability to monetize its patented technologies based on its past performance.

Fool contributor Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

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