Hartford Financial Services Group Inc., whose investment losses in 2008 led to a US bailout, was asked by regulators to explain why it expects its worst-performing holdings to rebound. The Securities and Exchange Commission instructed Hartford to provide more details on $2.1bn of securities that have traded at less than half of what the company says they're worth for more than a year. The unrealized loss on these investments, held by Hartford's life insurance subsidiary, totaled $1.5bn as of Dec. 31, the SEC said in a letter to the company dated April 13 and disclosed today.