Today's Primer Post

To say the U.S. stock market got 2013 off to a flying start would be a vast understatement: stocks had their best day Wednesday since December of 2011, featuring the Dow's first gain of more than 300 points since that time. The S&P 500 is just a few points shy of its highest level in a little over five years.

Whether the good mood continues could depend largely on some key economic data due today,most notably the monthly ADP report on private sector employment at 8:15 am ET. Economists expect the report to show that the U.S. economy added 150,000 private sector jobs in December, following November's addition of 118,000 jobs.

At 8:30 am,the Labor Department's weekly initial jobless claims report should show 363,000 first-time claims for unemployment benefits for the week ending December 29, according to consensus forecasts. That would be up from the prior week's 350,000.

U.S.automakers will be reporting their December sales figures throughout the morning, and the nation's chain stores will be reporting their same-store sales results for last month as well.

At 2 pm ET,the Federal Reserve is out with the minutes of the most recent FOMC meeting.

Discount retailer Family Dollar (FDO) is among the few companies set to report quarterly earnings this morning, while restaurant chain Sonic (SONC) will be out with its quarterly numbers after today's closing bell.

Advanced Micro Devices (AMD) is among our stocks to watch, with the chipmaker appointing interim chief financial officer Devinder Kumar as its permanent CFO. Kumar has been with the company for 28 years, most recently as corporate controller.

BuffaloWild Wings (BWLD) has a new major shareholder, with Steven Cohen's SAC Capital disclosing a 5% stake in the restaurant operator.

Microsoft (MSFT) has reportedly bought a home technology startup called id8 Group R2 Studios for an undisclosed amount. The company focuses on home and entertainment apps, such as a recently introduced Android app that lets users control home heating and lighting systems from smartphones.

Safeway (SWY) says its chairman and chief executive officer Steve Burd will retire at the supermarket operator's annual meeting on May 14. Burd joined Safeway in October 1992 and was named chief executive officer the following year. Safeway says it will consider both internal and external candidates as possible successors.

Starbucks (SBUX) is introducing $1 reusable plastic cups at its stores today. The coffee chain already gives small discounts for customers bringing in their own cups, and is hoping this will accelerate that trend.

Apple (AAPL) is said to be interested in buying mobile maps app company Waze, according to Tech Crunch. The report says Apple and Waze have been in talks but are somewhat far apart on price.

Google (GOOG) may be settling with the FTC as soon as today in the ongoing probe into Google's search practices, according to multiple reports. The probe centers around the contention that Google puts its own products higher up in search results than competitors, something that Google has repeatedly denied.

Costco (COST) is reporting a 9% increase in December same-store sales, above the 6.5% increase that analysts had been forecasting.