The NYSE Arca is hosting its first initial public offering, the IPO of Darwin Professional Underwriters Inc. which begins trading today.

This is the NYSE Arca’s first new listing since the formation of NYSE Group Inc. “We are pleased to welcome Darwin Professional Underwriters as the first addition to NYSE Arca,” said NYSE Group Inc. president and co-COO Catherine Kinney. “We look forward to providing Darwin with the superior market making, global brand visibility, and outstanding portfolio of services that issuers expect from the NYSE Group.”

“Darwin is excited about our initial public offering and listing on NYSE Arca,“ said Darwin Professional Underwriters CEO Stephen Sills. “We look forward to the next stage of our evolution, and an outstanding and productive partnership with NYSE Arca.”

In the NYSE Arca market model, listed issuers choose a “Lead Market Maker” responsible for maintaining tight spreads and providing the opportunity for price improvement.