The top after-market NASDAQ Stock Market gainers are: Warren Resources, MannKind Corp, Affymetrix, AutoNavi Holdings and Cathay General Bancorp. The top after-market NASDAQ Stock Market losers are: Research in Motion, China Finance Online, Merit Medical Systems, Mitcham Industries and Motricity.

Gainers:

Warren Resources, Inc. (NASDAQ:WRES) shares surged 6.71 percent to $3.66 in aftermarket trading session.

MannKind Corp. (NASDAQ:MNKD) shares advanced 4.97 percent to $3.80 in post market trading session. The stock has a 52 week low of $3.40 and 52 week high of $10.05 and has $473.08 million market capitalization.

Affymetrix, Inc. (NASDAQ:AFFX) shares gained 4.33 percent to $7.47 in aftermarket trading session. The company stock was upgraded to “neutral” rating at Wedbush.

AutoNavi Holdings Ltd. (NASDAQ:AMAP) shares gained 2.82 percent to $15.20 in aftermarket trading session.

Cathay General Bancorp (NASDAQ:CATY) shares advanced 2.62 percent to $15.64 in aftermarket trading session.

Losers:

Research in Motion Ltd. (NASDAQ:RIMM) shares slumped 14.35 in aftermarket trading session as its second quarter earnings forecast fell short of analysts’ expectations. The company expects second quarter earnings to be in the range of 0.75 to $1.05 per share on revenue of $4.2 to $4.8 billion, while analysts expect earnings of $1.40 per share on revenues of $5.46 billion.

Its first quarter net income declined to $695 million or $1.33 per share from $769 million or $1.38 per share in the same quarter last year. Revenue rose 16 percent to $4.91 billion from $4.24 billion in the same quarter a year-ago.

China Finance Online Co. Ltd. (NASDAQ:JRJC) shares plunged 6.06 percent to $3.72 in aftermarket trading session.

Merit Medical Systems, Inc. (NASDAQ:MMSI) shares declined 5.87 percent to $17.48 in post market trading session. The company announced that it plans to offer shares of its common stock in a public offering.

Mitcham Industries, Inc. (NASDAQ:MIND) shares declined 5.57 percent to $15.10 in post market trading session after the company announced that it is offering to sell shares of its common stock in an underwritten public offering.

Motricity, Inc. (NASDAQ:MOTR) shares declined 3.72 percent to $7.50 in aftermarket trading session.