Plug Power plunges nearly 8% on secondary offer, short sales

• Plug Power (PLUG -7.7%) earlier this morning tripped a Nasdaq short-sale circuit breaker following news late yesterday that it was selling an additional 15M common shares, sending shares nearly 8% lower.
• ~30% of PLUG’s shares are sold short, according to FactSet.
• Shares haven't been helped by a disclosure that the company sees Q1 revenues approximately at or moderately higher than the mid-point of previously announced guidance of $5M-$6M.
• Ballard Power (BLDP -0.1%), which supplies PLUG with its fuel cells, and FuelCell Energy (FCEL -1.5%) also are lower.