The Sezzle Inc(ASX: SZL) share price is trading lower on Friday following the release of its fourth quarter update. In afternoon trade, the buy now pay later provider’s shares are down 2% to $8.12. How did Sezzle perform in the fourth quarter? For the three months ended 31 December, Sezzle reported a 205.4% increase in underlying merchant sales (UMS) to US$320.8 million ($419.8 million). This was also a 40.6% quarter on quarter increase. This meant that at the end of the period, Sezzle’s annualised run rate UMS reached US$1.36 billion. According to the release, this strong growth was driven by an increase in active customers, merchants, and repeat usage.