Honolulu-based Barnwell Industries Inc., which derives the majority of its revenue from oil and natural gas operations in Canada, said today it knows of no reason why its stock has more than doubled since the start of the year.

The shares closed up $1.01, or 12.7 percent, at $8.94 today on the American Stock Exchange. Barnwell’s stock, which began the year at $3.62, is up 147.2 percent in the first nine trading days of 2011.

So far this week, Barnwell’s stock has risen 4.6 percent, 22.4 percent and 30.6 percent before another big gain today.

Barnwell President Alex Kinzler said that the company was notified by the New York Stock Exchange, which oversees the AMEX, to put out a letter today explaining the stock’s movement. But Kinzler said after the market closed today that heavy selling held down the shares at the end of the year and there appears to be a delayed reaction to the stock being “undervalued.”

The company’s other operations consist of a development on the Big Island and statewide water drilling operations.