Polymarket signage on the floor of the New York Stock Exchange.Photographer: Michael Nagle/BloombergPolymarket has been recruiting new staff members for an internal market making team that could face off against customers on the company’s exchange, even though a similar feature has exposed its chief rival to criticism. The New York-based prediction market startup has recently spoken to traders including sports bettors about joining the new unit, according to people familiar with the matter who a...