Benzinga's Top #PreMarket Losers

Prana Biotechnology

dipped 66.94% to $3.26 in the pre-market session on failed Phase 2 Alzheimer's trial results. MannKind

dipped 6.83% to $4.50 in pre-market trading after dropping 7.12% on Friday. General Motors Company

fell 1.30% to $34.28 in pre-market trading. Federal regulators twice declined to open formal investigations into GM cars with faulty ignition switches, according to the Wall Street Journal. BlackBerry

shares dropped 1.19% to $8.31 in pre-market trading after falling 7.07% on Friday. Analysts at Credit Suisse downgraded BlackBerry from neutral to underperform and lowered the target price from $7 to $6.