Alt A lenders showed considerable muscle during the first half of the year, a new Inside Alternative Mortgage analysis reveals. To say that the Alt A market is running red hot in 2005 is a bit of an understatement: volume in the sector rose 81 percent, on a year-to-year basis, at the year’s midway mark. Putting that performance in context, conventional conforming and government-insured markets are down from year-ago levels. And Alt A lenders are… [One data table included]