Several mid-sized mortgage lenders have seized on this year’s favorable market for initial public offerings to fund their growth strategies. The rebounding U.S. economy has paved the way for one of the strongest initial public offering, or IPO, markets in years. According to research firm Renaissance Capital, there have been 81 offerings completed, yielding $19.7 billion, compared to 68 in all of 2003, totaling $15.2 billion.