Dustin Shindo, CEO of the Kapolei-based company, told PBN he had "no idea" what caused the jump, which he said was even more perplexing because more than 1.6 million shares were traded, seven times more than the daily average of about 222,000.

Day traders posting on the company's Yahoo! Finance message board say the run began when an alert on insightertrading.com recommended buying stock in Hoku (Nasdaq: HOKU).

The alert said the company's stock had probably hit bottom on Aug. 16 when it traded at $2.12. Most of the posters on the message board said they expected the company's stock to have a similar run-up on Wednesday.

The company's last official announcement came Aug. 16, when it said it installed the last of 10 power plants it had to furnish as part of its $4.5-million "field test" contract with the U.S. Navy.

Since going public a year ago, Hoku's stock price has traded as high as $13.

Hoku's core product is its membrane electrode assembly, the brain that controls fuel cells. Fuel cells are essentially self-sustaining batteries and are a promising alternative energy source to power vehicles and homes.