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.

Expect a weak start to the stock market today, as the Dow Jones Industrial Average (^DJI -0.98%) lost a moderate 20 points in premarket trading this morning. Still, stocks could turn up the volatility this afternoon, as the Federal Reserve is set to release minutes from its December meeting at 2 p.m. EST. The central bank decided at that meeting to begin scaling back its stimulus measures, and the minutes could give investors clues as to just how quickly that process will unfold. Meanwhile, news is breaking this morning on a few stocks that might see heavy trading in today's session, including Microsoft (MSFT -2.45%), Monsanto (MON), and Constellation Brands (STZ 0.06%).

Microsoft is closer to ending its CEO hunt, if only by the process of elimination. Alan Mulally, Ford's (F 0.69%) CEO, said yesterday that he would not be headed to Redmond to take over for retiring Steve Ballmer. Microsoft had hoped to find a new leader before the end of 2013, according to The Wall Street Journal, but that search has dragged on to the point that it's starting to affect morale at the software giant. Microsoft's shares are down 0.8% in premarket trading, while Ford's stock is up 1.8%.

Constellation Brands shares could hit a new all-time high today after the company this morning reported strong earnings results for its fiscal 2014 third quarter. Revenue leapt by 88%, reaching $1.4 billion as its new beer brand business performed well through the holiday season. Constellation's profit nearly doubled over last year's haul, to $217 million. The wine, beer, and spirits company also boosted its outlook for the year, saying that it now expects earnings of about $3.15 a share, 40% higher than last year's result. The stock is up 6.8% in premarket trading.

Finally, Monsanto this morning reported adjusted profit of $0.67 a share for its fiscal first quarter, which was higher than the $0.64 that analysts expected. Sales also came in above expectations, at $3.14 billion. The seed giant saw profitability tick higher, as gross profit rose to 50% of sales from 48% a year earlier. Monsanto is set to deliver its largest soybean launch ever in the months ahead, and it affirmed its outlook for full-year earnings of about $5.10 a share. The stock is unchanged in premarket trading.