Buffalo Wild Wings (BWLD) is significantly higher after the restaurant chain topped analysts' second-quarter earnings expectations.

After Tuesday's closing bell, Buffalo Wild Wings reported a quarterly profit of $9.2 million, or 50 cents per share, up from its year-ago earnings of $7.0 million, or 39 cents per share. Revenue for the period climbed 12.4% to $145.7 million. Analysts surveyed by Thomson Reuters were anticipating earnings of just 42 cents per share on $141.5 million in revenue.

When a country's economy gets stronger, its currency follows. The recent unemployment report on Dec. 4 was much better than expected. If the economy is stronger, the Federal Reserve will raise interest rates. Both of these factors have sparked a dollar rally.

The rally was most likely caused by short-covering, the Financial Times reports. When a trader "sells short," he or she must "buy" to cover the position. The Chicago Mercantile Exchange (CME), where currency contracts are traded, keeps a running tally of the long and short positions in each currency. On Dec. 1, there were 172,367 net short dollar positions. By Dec. 8, this number had dropped to 107,284, The value of this shift in net positions was $9.8 billion dollars.

Yingli Green Energy (YGE) traded sharply higher Friday in the wake of its third-quarter results. The solar issue reported that its quarterly earnings contracted 18% to $17.7 million, or 12 cents per American depositary share (ADS). Excluding items, such as stock compensation, earnings weighed in at 18 cents per ADS. Revenue for the period edged 0.7% higher to arrive at $325.9 million.

Ahead of the report, analysts were looking for a profit of 16 cents per ADS on $331 million in revenue. Despite the revenue miss, YGE surged into the black right out of the gate. In addition to the stronger-than-expected profit number, traders were no doubt enthused by an 80% jump in shipments from second-quarter levels.