So far this year, 43 companies have made their publicly traded debuts. As a whole, IPOs have experienced a solid year thus far, raising nearly $7 billion YTD and averaging returns of 22%. Last week alone, seven companies issued IPOs, including four companies trading at valuations of over $1 billion. Among them were popular online retailer Esty, which specializes in selling handmade goods, and high-frequency trading firm Virtu Financial (VIRT).