Klarna’s IPO has been years in the making. - Stefani Reynolds/Bloomberg News Shares of online-payments provider Klarna jumped 30% at the open Wednesday in the Swedish firm’s NYSE debut, the latest sign that a long-suffering IPO market is alive and kicking. Klarna started trading at $52 early Wednesday afternoon, a day after its initial public offering price was set above the previously estimated range. Shares traded as high as $57.20 before closing up 15% at $45.82. Most Read from The Wall Street Journa ...