As U.S. lawmakers and regulators cracked down on big banks like JPMorgan Chase (JPM - Get Report) and Bank of America  (BAC - Get Report) in the aftermath of the 2008 financial crisis, a chorus of analysts, economists and banking executives warned that more lending business would simply migrate to companies outside of the strictest government oversight. A race to the bottom, as it were. 

And that's exactly what happened.  

A top Federal Reserve official is now warning of new risks from lenders that operate outside of the strictest banking-industry rules.

Those include big private-equity firms like Blackstone  (BX - Get Report) and Ares Management  (ARES - Get Report) that have pushed to provide more financing to small- and medium-size businesses. It also encompasses non-bank mortgage lenders like PHH Corp. (PHH)  and Quicken Loans, a part of the family of companies overseen by founder and billionaire Dan Gilbert, owner the Cleveland Cavaliers National Basketball Association franchise.

Randal Quarles, the Federal Reserve's vice chair for supervision, said Thursday in a speech in Frankfurt that such non-bank companies - often referred to as "shadow banks" - now represent about 50% of total global financial assets, up from about 45% in 2009.

"Nonbank financing often features high leverage, maturity and liquidity mismatches, opaque structures and concentrated holdings of risky assets," Quarles said. "Nonbank financing can also lead to lower lending standards, bidding up the price of risky assets and sending an encouraging signal to credit underwriters. All of these channels played a role in the recent global financial crisis."

There's a also the risk of "interconnectedness between nonbank financial firms and the banking system," he said, in a reference to the risk that losses suffered by non-banks might in turn cascade to the closely monitored banking system. 

The warning from Quarles comes amid heightened scrutiny of so-called "leveraged loans," or those made to companies with junky credit ratings.

Such loans swelled by 15% last year to a record $1.3 trillion, according to Fitch Ratings, and underwriters have loosened their underwriting standards dramatically to attract borrowers, while reducing protections for creditors. The growth has elicited alarms from U.S. bank regulators, the International Monetary Fund, Federal Reserve Bank of Dallas President Robert Kaplan and U.S. Sen. Elizabeth Warren, a Massachusetts Democrat who is seeking the Democratic nomination for  president.

Standard & Poor's warned in November that big U.S. banks often stand behind the shadowy, less-regulated lenders at the heart of the market -- through underwriting commitments, credit lines for borrowers and off-balance-sheet funding facilities for mutual funds and other investment vehicles that eventually buy the loans.

Quarles said in the speech that he wonders if regulations are adequate to police the new risks posed by non-banking lenders.

"Have we modeled the risks from nonbank financing accurately?" he said. "Have we missed a crucial new source of systemic risk?"

He also noted the risk of disruption to the financial industry from the growing push by technology companies into lending, asset management, payments and insurance -- broadly grouped under the label of "fintech." Last week, Apple  (AAPL - Get Report) , the iPhone maker, announced plans to offer a new credit card, though that effort is backed by the giant Wall Street firm Goldman Sachs  (GS - Get Report) , which is licensed as a bank.

"Technological innovation offers the promise of a substantially more efficient financial system, but new systems, processes, and types of businesses will bring with them novel fragilities," Quarles said. 

JPMorgan, Apple and Goldman Sachs are holdings in Jim Cramer's Action Alerts PLUS member club. Want to be alerted before Jim Cramer buys or sells the stocks? Learn more now.

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