(Read More: Pimco Flagship Fund Loses Big on Bond Shock)
At the core of the uncertainty is the Federal Reserve, whose chairman, Ben Bernanke, helped fuel a bond exodus when he offered some cryptic remarks last week regarding when the central bank might halt its bond-buying program and, ultimately, begin raising interest rates.
That Bernanke may have been doing little more than floating a trial balloon has mattered little—the market's fragile psyche took the chairman's words to mean that the liquidity party was coming to an end and the days of free money with it.
In fact, investors essentially dismissed Bernanke's critical caveat that all decisions would be data-driven.
(Read More: Taper Tipoff? Bernanke Hints Easing End Is Nearing)
In doing so, they showed that the chairman's words not only may be losing their bite, but the Fed's actions may be also.
The third leg of quantitative easing—$85 billion a month in purchases of Treasurys and mortgage-backed securities—has seen its effectiveness diminish over the past month, with rising yields and a 4 percent drop in the stock market.
"We think the Fed is aware of the diminishing returns to QE, and in the face of stabilizing economic data, this led them to signal that they would begin to withdraw from the program," said Adam Parker, chief U.S. equity strategist at Morgan Stanley.
That signal, though, has come amid an economic backdrop that hardly seems inspiring.
Wednesday's revision of second-quarter gross domestic product took the final reading all the way down to 1.8 percent from a previously revised 2.4 percent, which in itself came down from initial estimates closer to 3 percent.
(Read More: First-Quarter GDP Gets a Haircut, Rises Just 1.8%)
Other data have pointed to only modest gains in employment and inflation well below the Fed's 2.5 percent target.
To say the least, such soft numbers complicate a Fed exit.
Hints of tapering asset purchases and interest rate hikes has been unpopular even within the Fed.
"A more prudent approach would be to wait for more tangible signs that the economy was strengthening and inflation was on a path to return toward target," St. Louis Fed President Jim Bullard said in a statement following last week's Open Market Committee meeting, where he cast one of two dissenting votes against the communique issued.
Minneapolis Fed President Narayana Kocherlakota, during a CNBC interview, echoed concerns about the Fed's choice of language. He said markets need to understand that the central bank isn't going anywhere, even if it decelerates its easing pace.
(Read More: Fed Has to Be Clearer on Rates: Fed's Kocherlakota)
"We sort of take it for granted that people understand we're going to be in the business of accommodation long after the asset purchases end," he said. "We have to do more to make those qualitative points. ... If we do that I think we'll be more easily able to deal with what really is a minor tweak in policy, which is talking about how long the flow of purchases will continue."
Markets, though, are not interpreting the changes as "minor."
"The increase in corporate yields is on par with the most rapid nonfinancial-crisis-related selloffs we have seen over the past dozen years or so—and dwarfs in particular the most recent experience toward the end of 2010," said Hans Mikkelsen, credit strategist at Bank of America Merrill Lynch, a firm that has devoted much time and energy over the past nine months or so espousing a "Great Rotation" theme of money flowing out of bonds and into stocks.