shares of aspen aerogels inc fell more than 10 in premarket trading wednesday after the maker of aerogel insulation said it was raising 240 million in a dilutive public stock offering the northborough mass company said it is selling nearly 253 million shares at 950 apiece below tuesdays closing price of 1134 aspen which had about 408 million shares outstanding before the offering said it plans to use proceeds from the offering to partially fund the construction of its second aerogel manufacturing plant in statesboro ga aspen shares were recently down nearly 13 to 991 in premarket trading