But in conversations this week with a wide range of investors, Wall Street executives, and economists, no one told me they thought that the Third Avenue fund’s liquidation was likely to set off another crisis. And while bubbles may yet emerge, by their very nature they’re likely to be found somewhere entirely unexpected — not a closely watched, highly liquid market like the $1.3 trillion United States junk bond market.

Image Howard Marks, co-chairman of Oaktree Capital Management, worries about excess in the markets, but agreed that the Third Avenue fund was an outlier. Credit... Jennifer S. Altman for The New York Times

“The Third Avenue situation is unique,” said Gary Cohn, president of Goldman Sachs, who has been in frequent contact with clients throughout the week. “They owned really low-credit-rated products compared to the typical high-yield fund. The long-term impact of rising rates remains a big question mark. But no one thinks that the collapse of Third Avenue is going to contaminate the world.”

In part that’s because today’s junk bond market — and the institutions that invest in it — lack two important ingredients of past crises: high leverage (heavy borrowing to finance the purchase of assets) and concentrated bets. While Third Avenue’s portfolio was concentrated in thinly traded, obscure bonds, it had no leverage. Its failure didn’t put any lender in peril, the way the collapse of Lehman Brothers led to crises at A.I.G. and throughout Wall Street.

And most junk bond funds, including the two largest high-yield E.T.F.s, also have no leverage and are highly diversified, with hundreds of securities across all industries. Goldman said this week in a note to clients that outside the battered energy sector, “banks are still upbeat about credit quality.”

Mark Wiedman, global head of the iShares E.T.F. business at BlackRock, said that the characteristics of E.T.F.s made them far safer than owning individual junk bonds. “The vast majority of E.T.F.s, including all of ours, are unlevered, passive vehicles,” he said. “They’re boring.”

Unlike mutual funds, which may need to sell underlying fund positions to meet shareholder redemptions, E.T.F. shares trade like stocks. Last Friday, Blackrock’s flagship junk bond E.T.F., the iShares iBoxx $ High Yield Corporate Bond E.T.F., experienced a surge in trading — $4.3 billion, four times the record daily volume before that week. (On an average day the fund trades about $700 million worth of shares.) On Monday trading hit $3 billion.