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.

According to stock index futures as of 7:45 a.m. EDT, the Dow Jones Industrial Average (^DJI -0.11%) will open modestly higher, rising by 22 points at the opening bell. Global markets gained overnight after news broke that President Obama will nominate Janet Yellen to be the next leader of the Federal Reserve.

Yellen has worked closely with the current chairman, Ben Bernanke, and has supported the Fed's efforts to stimulate growth. Her nomination makes it less likely that the Fed will quickly change course from its easy-money approach.

With that in mind, here are some individual stock stories to watch for in today's market.

Costco (COST 0.17%) managed to eke out growth during a rough quarter for retailers. The company reported $31.77 billion in sales, which was 1% better than the year-ago quarter. Earnings per share came in at $1.40, just a penny better than last year's haul. Revenue and profit were both shy of Wall Street's expectations. Still, comparable-sales growth was a solid 5% for the quarter, and expansion plans look strong, with 11 new warehouses set to open by the end of the year. Costco shares are down 1.3% in premarket trading.

Jos. A. Bank (NASDAQ: JOSB) wants to buy its rival. The clothing retailer confirmed this morning that it made an offer to acquire The Men's Warehouse (TLRD) for $48 per share. The deal would be worth $2.3 billion in cash to Men's Warehouse shareholders and would be funded by a mixture of Jos. A. Bank's cash on hand and new equity and debt. Both stocks are up big on the news this morning, with The Men's Warehouse gaining 31% and Jos. A. Bank 9.7% higher in premarket trading.

Finally, Family Dollar's (FDO.DL) growth streak is intact. It reported a 15% bounce in earnings this morning after sales improved by 6% to reach $2.5 billion. Key to that revenue boost was Family Dollar's food and other consumables' sales, which grew by 8.6%. The downside to selling more food, though, is less profit. Lower-margin consumables sales helped pushed gross profit margin down to 34.5% from last quarter's 34.7% margin. Family Dollar's stock is down 3% in premarket trading.