Federal Reserve policy has been credited often with pushing up stock prices, but one research firm believes the central bank has pushed all asset prices to extreme levels.
"We think investors with a longer-term outlook should tread carefully in financial markets," TrimTabs said in its widely followed weekly market analysis. "The Federal Reserve and its fellow central banks have succeeded in making almost every major asset class in the world overpriced."
While the S&P 500 has climbed more than 15 percent year-to-date, other risk assets have surged as well, while the Fed has expanded its balance sheet past $3.4 trillion in efforts to spur growth.
TrimTabs cites a few: Global junk bond issuance (a record $254 billion through May); house flipping in California, which a recent Wall Street Journal report pegged at its fastest pace since 2005; and the increased creation of collateralized debt obligations, the instruments that helped create the financial crisis. They are around pre-crisis levels.
(Read More: Junk Bond Volume Piling Up, but Trouble Lurks)
"It is amazing how quickly bubble behaviors from the last decade have come back," TrimTabs CEO David Satschi noted.