One Wall Street analyst is sounding the alarm on two high-profile loans. A Wall Street analyst has lowered his rating on Bank OZK (OZK -14.67%) to sell from buy due to concerns about some of the bank's largest loans. Investors are heeding the alarm, sending shares of Bank OZK down 16% as of noon ET. Big projects, big risk Bank OZK, formerly known as Bank of the Ozarks, operates from 228 branches spread across five Southeastern states. Is Bank OZK a buy following the downgrade? Bank OZK's loan book has held ...