The majority of publicly traded business development companies (BDCs) — the visible part of the private credit market — have turned unprofitable due to falling asset values and rising costs, a Reuters analysis shows, in the latest sign of pressure building in this highly leveraged corner of finance. The $3.5 trillion private credit industry, where specialist funds step into a role traditionally held by banks to lend to mid-sized companies, has lately come under stress due in part to its…