Sterling Bancshares Inc. (Nasdaq: SBIBW) flew 60 percent in price to $3.12. Volume was 101,438, or five times its full-day volume average, amid reports this week that Cullen/Frost Bankers, Inc. may be acquiring the smaller bank.

Citigroup Inc. (NYSE: C) flew off the shelves Tuesday, dealt in 731,126,655 shares Thursday, already surpassing a full-day average of 549,838,000. Prices for C fell 5.5 percent to $4.86. Citigroup reported a $1.3 billion profit, compared with a $7.6 billion loss a year earlier. Revenue jumped to $18.4 billion, from $5.4 billion a year earlier, but fell more than 11% from the third quarter.

Alexza Pharmaceuticals Inc. (Nasdaq: ALXA) fell 19.2 percent in early trading to $1.35. Volume for the stock was 1,784,554 shares, nearly double its all-day average, on word that the company will file a new application for its drug candidate Adusuve Staccato in July.