Beckman Coulter Inc. (NYSE: BEC) shares gained 9.7 percent to $82.49, on volume of nearly 27 million shares, towering over its average of 1.3 million, after industrial company Danaher Corp. (NYSE: DHR) said it would buy the medical-diagnostics firm in a deal valued at about $6.8 billion. Danaher shares traveled higher 3.5 percent to $49.68.

Citigroup Inc. (NYSE: C) was busy on the markets Monday, trading in 75 million shares, catching up on a daily average of 561 million. Share prices added 0.9 percent to $4.86. C announced that its Global Transaction Services has launched a new module within its TreasuryVision® portal that simplifies how companies manage internal lending relationships between their legal entities.

Dearborn Bancorp Inc. (Nasdaq: DEAR) lost 11 percent Monday to $1.54. Volume for the stock was 165,420 shares, leading its normal daily average of 116,091, after reporting Friday a quarterly loss of $2.4 million, still less than half its loss in the prior-year quarter.