Alarms Ringing for Office Market: When the loan on Philadelphia’s largest stand-alone office building at 1500 Market St. moved to special servicing in August, it didn’t register much alarm at the time, according to a new report by Morningstar Credit Information & Analytics. After all, the property's performance metrics were significantly below underwritten expectations for a loan securitized in commercial mortgage-backed securities deal JPMCC 2020-MKST.