This week, these five stocks have the best ratings in Surprise, one of the eight Fundamental Categories on Portfolio Grader.

Aspen Aerogels Inc. The company also gets A’s in sales growth and earnings surprise. For more information, get Portfolio Grader’s complete analysis of ASPN stock.

Spark Networks, Inc. (LOV) is a provider of online personals services in the United States and internationally. The company also gets A’s in earnings surprise. For more information, get Portfolio Grader’s complete analysis of LOV stock.

Tanger Factory Outlet Centers, Inc. (SKT) owns and operates factory outlet centers in the United States. The company also gets A’s in operating margin growth, earnings growth, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of SKT stock.

Silver Standard Resources Inc. (SSRI) is a silver exploration company focused on acquiring and developing silver resources on a global basis. The company also gets A’s in earnings surprise and earnings momentum. For more information, get Portfolio Grader’s complete analysis of SSRI stock.

Merus Labs International Inc. (MSLI) acquires and licenses niche branded pharmaceutical products in the United States and Canada. The company also gets A’s in sales growth and earnings surprise. For more information, get Portfolio Grader’s complete analysis of MSLI stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.