Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

Stocks have exploded upward in the wake of the Federal Reserve's announcement that it will begin tapering quantitative easing. The Dow Jones Industrial Average (^DJI 0.61%), which had been hanging flat all day, has roared higher by nearly 160  points as of 2:30 p.m. EST, with nearly all of its stocks in the green. However, Microsoft (MSFT 1.44%) has struggled mightily today, losing around 1%. Let's catch up on what you need to know.

A big day from the Fed
Many economists projected that the Fed would wait until later in 2014 to launch tapering, but the central bank said today that it will reduce bond purchases from $85 billion per month to $75 billion beginning in January. So why have markets soared despite so much fear around tapering recently? The Fed said that while the economy's rebounding enough to justify tapering, it will keep short-term low interest rates around for some time.

That's pushed stocks higher across the board today, but Microsoft's getting no traction after disappointing impatient investors with the news that it likely won't announce a successor to CEO Steve Ballmer until sometime in 2014. The company's leadership search has garnered quite a lot of attention lately, and while it's pivotal that Microsoft find a strong leader -- particularly as the company tries to make a bigger push into the consumer hardware market while maintaining its dominance in software and business solutions – investors need not be in a rush to force the company's hand. A slow and steady selection process is best for Microsoft's future.

The next CEO will face a tall task. The company's purchase of Nokia's mobile unit comes as Microsoft looks to challenge its traditional rivals in the phone-making business, a new direction that likely will see some bumps in the road. Microsoft's still pushing its other recent hardware ventures, such as tablets. While the company's Windows tablets have gained more than 3% of market share this year, Microsoft still has a long way to go before it will challenge traditional leaders in the space.

Merck's (MRK 0.34%) stock has taken off from earlier sluggish gains to rise roughly 0.95% so far. The company today announced that it will team up with Big Pharma rival GlaxoSmithKline (GSK 0.98%) to battle kidney cancer, collaborating in a project that will see Merck's developmental drug MK-3475 paired with Glaxo's renal cell carcinoma drug Votrient.

While Merck and Glaxo didn't mention when studies will begin, it's a sure sign for Merck and its investors of the growing clout of MK-3475. The drug's one of Merck's lone developmental stars in a pipeline that has left many observers disappointed lately. The more Merck can do with this drug the better for the company's future.