Shares of eBay Inc. are up 2.7% in Wednesday morning trading after analysts at Morgan Stanley "double upgraded" the stock to overweight from underweight. The analysts, led by Brian Nowak, wrote that eBay could benefit as it starts "intermediating" payments on its site. "We are bullish about this initiative as we've seen other leading platforms (Amazon.com Inc. Booking Holdings Inc. Uber, etc.) observe higher user conversion/spend from more integrated/comprehensive payment offerings, which we now expect to be the case for eBay's marketplace," Nowak wrote. PayPal Holdings Inc. has served as the merchant of record for transactions on eBay, but eBay will start to take over that role. Nowak is also upbeat on eBay's ad business, which he estimates could reach "$450 million of high-margin revenue." eBay shares are up 22% over the past 12 months, while the S&P 500 has gained 16%.