Crane, appearing Monday before the Joint Finance-Appropriations Committee, wouldn't answer questions from Sen. Dean Cameron, a Republican from Rupert, about why his office made the transactions that inflated the securities' value by millions.
According to an audit released last week, Crane's "inappropriate" transfers have cost Idaho state taxpayers $10.2 million, though additional losses of millions more could come.
The state audit concluded Crane's office overrode internal controls and unnecessarily exposed state money to "disproportionate risk."
Crane declined to answer reporters' questions Monday, with staff contending the matter was too complex.
Crane contends his office did a "yeoman's job" shepherding taxpayer money.