Average U.S. rates for fixed mortgages rose this week to their highest levels in two years, mortgage buyer Freddie Mac said Thursday. The average rate on the 30-year loan jumped to 4.58 percent, up from 4.40 percent last week.The dollar was little changed against the euro and rose against the Japanese yen. Among other stocks making big moves: â¿¿ Nasdaq OMX fell $1.08, or 3.4 percent, to $30.46 after Thursday's trading glitch. â¿¿ Hewlett-Packard fell $3.16, or 13 percent, to $22.22 after the company reported weak demand for personal computers and falling revenue late Wednesday. The company's earnings were below Wall Street's expectations. â¿¿Dollar Tree rose $1.29 cents, or 2.5 percent, to $53.13 after the company reported earnings that surpassed the expectations of Wall Street analysts. The company also raised the lower end of its full-year earnings forecast.