Benzinga's Top Pre-Market Losers

Xyratex Ltd

shares dropped 13.79% to $7.50 in pre-market trading. Xyratex posted downbeat third-quarter results. Rigel Pharmaceuticals

dipped 5.02% to $9.83 in the pre-market session. Rigel Pharmaceuticals intends to offer and sell shares of its common stock in an underwritten public offering. Monsanto Co

shares fell 3.05% to $88.17 in the pre-market trading. Monsanto posted a Q4 net loss of $229 million, versus a year-ago net loss of $112 million. Walgreen Co

dipped 2.47% to $36.00 in the pre-market session. Walgreen reported a 7.8% y/y drop in its September sales.