The Nasdaq Composite stock market index is seen inside its studios at Times Square in New York in this file image
The Nasdaq Composite stock market index is seen inside its studios at Times Square in New York in this file image from April 1, 2011. Reuters

The top after-market NASDAQ stock market movers on Oct.28 include Momenta Pharmaceuticals, HMS Holdings, Clayton Williams Energy, MedAssets, Fuel Systems Solutions and Netgear.

Gainers

Shares of Momenta Pharmaceuticals, Inc. (NASDAQ: MNTA) climbed about 20 percent, or $2.36, to $14.60 after it won a court ruling that will temporarily block rivals from selling a generic version of its anti-clotting drug, Lovenox.

HMS Holdings Corp. (NASDAQ: HMSY) stock gained about 15 percent, or $3.53, to $27.13 after it reported better-than-expected third quarter earnings on 15 percent growth in revenues. For the third quarter, the company earned 17 cents a share, up from analysts' consensus expectation of 16 cents.

Shares of Clayton Williams Energy, Inc. (NASDAQ: CWEI) rose 9.7 percent, or $6.80, to $77.01 after it reported strong third-quarter results. Net income attributable to stockholders was $74.5 million, or $6.13 per share, compared to $11.6 million, or 96 cents per share, last year.

Losers

Shares of MedAssets, Inc. (NASDAQ: MDAS) plunged 12 percent, or $1.35, to $9.85. The stock closed regular trading session 13 percent higher at $11.20.

Shares of Fuel Systems Solutions, Inc. (NASDAQ: FSYS) were down about 7 percent, or $1.63, to $22.24. They ended Friday's regular trading session up 1.14 percent to $23.87.

Shares of Netgear, Inc. (NASDAQ: NTGR) slipped 6.45 percent, or $2.28, to $33.08. The stock closed Friday's regular trading session up 7 percent to $35.36.