With the Federal Reserve offering the market essentially unlimited support, including tolerating more inflation than ever before, growing numbers of analysts have basically given up on predicting what this could mean for the market as they grapple with the abandonment of long-held assumptions, said CNBC.

The Federal Reserve has played a major role in the response to the coronavirus pandemic's economic effects: It has pledged to buy an effectively unlimited amount of risky corporate debt to keep credit markets flowing smoothly, set aside hundreds of billions of dollars for Main Street Lending Program business loans and, most recently, announced a major shift in inflation policy that tolerates short spikes above the set target so long as they smooth out in the average.

Because these central bank's actions are unprecedented in scale and scope, analysts are increasingly declining to make forecasts, as there's no way to tell just how high valuations can get in this environment. CNBC said this is at least partially due to the fact that the things that tend to stop market rallies, inflation and interest rate increases, seem unlikely to emerge in the near future, and so it would seem that the question isn't whether markets will rise but how much and for how long. If anything, analysts believe earnings estimates are actually too low, given current market conditions.

Yet CFOs are wary that the current boom in stocks might be too much of a good thing, said CNN Business. A recent poll by Deloitte of Fortune 500 CFOs found that a staggering 84 percent believe the stock market is overvalued, up from the still-quite-high 55 percent who believed this way a quarter ago. Just 2 percent think the market is undervalued. The rally seems to clash with CFOs' own assessment of the economy, as 60 percent say current conditions are either bad or terrible, with just 7 percent saying they're good.