Shares ​of Lincoln International gained 12.6% in their New York Stock ‌Exchange ⁠debut ⁠on Wednesday, valuing the investment ​bank at about $2.3 billion.The Chicago, ​Illinois-based firm's stock opened at $22.51 apiece, above the ​offer price of $20.Lincoln ⁠and ‌selling stockholders ​sold ​21 million shares ⁠at the top of the marketed ​range of $18 and $20 each ​to raise $421 million in the IPO.Investment bank IPOs in New York have been ‌scarce over the past decade or so, ​with some ​boutique ⁠advisory firms choosing to sell themselves before reaching the scale ​needed to go public.