Omeros Corp. (Nasdaq: OMER) shares gained 10.6% to $6.69. Volume was 154,491 shares, or 2 and a half times the norm, after the biotechnology company said its potential eye-surgery treatment met key goals in a mid-stage study.

Sirius XM Radio Inc. (Nasdaq: SIRI) traded in 44.7 million shares by noon ET Wednesday, in contrast to a daily average of 55.9 million. Share prices dipped a bit, though, by 2.4% to $1.67, after Howard Stern sued the satellite radio provider and at least one analyst cut his rating on the stock.

Cree Inc. (Nasdaq: CREE) shares fell 11.7% to $43.29, on volume of 14.2 million, towering over its average of 3.3 million, after the LED manufacturer trimmed its third-quarter revenue forecast.