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.

The long-awaited day has finally arrived -- the Federal Reserve has begun tapering its monthly monetary easing program known as QE3.

According to Federal Reserve chairman Ben Bernanke in his final address before his term expires, the Fed will begin tapering its monthly bond-buying program by $10 billion per month. (To add context, the Fed has been pumping $85 billion into the economy on a monthly basis.) Bernanke did note, however, that the first increase in the federal funds rate may not even occur in 2016, according to the sentiment of three Fed governors.

Simply put, the expectation for months had been that the broad-based S&P 500 (SNPINDEX:^GSPC) would tank on news of the start of QE3 tapering, but we're seeing the exact opposite effect today with the index exploding higher. This appears to be nothing more than confirmation from recent economic data that the U.S. economy should be able to stand on its own two feet, and that investors now have tangible clarity as to when and how the taper will commence.

By day's end the S&P 500 rocketed higher by 29.65 points (1.66%), to close at 1,810.65, another all-time closing high.

Leading the pack higher today is media solutions provider Valassis Communications (UNKNOWN:VCI.DL), which advanced 22.3% after agreeing to be acquired by Harland Clarke for $1.3 billion, or $34.04 per share in cash. Valassis, which is the company behind Redplum advertising inserts, is getting a relatively small premium relative to its 2014 earnings; however, considering that Valassis' top-line growth is relatively stagnant, shareholders should be pleased with the deal. Both companies' board of directors approved the deal.

Struggling biopharmaceutical company Ariad Pharmaceuticals (NASDAQ:ARIA) surged 19.7% following word that the European Medicines Agency had added its blood cancer drug Iclusig to its meeting agenda for the month of December. Ariad shares already surged in late November on the expectation that Iclusig would remain on the market to treat leukemia patients, but would merely have more restrictions added to patients taking the drug. As a refresher, Iclusig has been linked with a higher incidence of blood clots in patients taking the drug according to Ariad's two-year follow-up study. This meeting with the EMA could be positive news as it may signal Iclusig's ability to remain on pharmacy shelves in the EU. As for me, I still advocate steering clear of this situation until the FDA doles out its decision on Iclusig remaining on the market.

Finally, biopharmaceutical company DepoMed (NASDAQ:ASRT) popped by 17.6% after announcing the purchase of migraine medication Cambia from Nautilus Neurosciences for $48.7 million. DepoMed could be on the line for an additional $5 million in payments depending on whether or not Cambia meets certain net annual sales milestones; but the deal, overall, looks like a winner for a company looking to diversify its product pipeline and lock in drugs free of generic competition. Cambia sales grew by more than 30% last quarter, and are protected by patent for the next 10 years. In addition, it's the only non-steroidal anti-inflammatory drug approved to treat migraines, leaving it in a niche market position. As I stated earlier today, I'd much prefer to wait for DepoMed to be back in the black before chasing it higher, but this is nonetheless a smart strategic move for the company.