The Dow (NYSE:DIA) posted triple digit gains on Thursday, as gold (NYSE:GLD) and silver (NYSE:SLV) finally decided to take a breather.

These 4 companies reported earnings after the bell on Thursday.  Should you trade these stocks Friday?

1)  Kodiak Oil & Gas (AMEX:KOG): Shares fell 4.37% after the company released fourth quarter results.  Although oil and gas sales increased 131% from last year, the company still reported a net loss of $4.4 million ( 3 cents per share). Included in the 2010 net loss calculation are unrealized derivative losses of $4.6 million.

2) Weyco Group (NASDAQ:WEYS): The mens footwear distributor reported a 7% increase in sales for the fourth quarter.  Net sales were $62.3 million, compared to $58.4 million in the same period last year.  The company earned $5.1 million (45 cents per share) for the quarter.  The stock currently pays a dividend yield of 2.6%.

3) DexCom, Inc. (NASDAQ:DXCM): The medical device manufacturer reported a net loss of $9.8 million (16 cents per share).  Despite the loss, it was actually an improvement from last year’s $11.5 million (25 cents per share) loss for the same quarter.  On a positive note, sales for the company climbed 49% to $15.6 million.

4) Energy Recovery, Inc. (NASDAQ:ERII): Shares took a beating of nearly 7% after the company reported a poor fourth quarter.  Revenue fell from $15.7 million to $13 million.  Analysts were expecting revenue of about $18 million for the quarter.  The company also gave a disappointing outlook for 2011, as it expects to lose 13-19 cents per share for the year.

Disclosure: No positions

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