What drives stocks (other than cheap funding from FED), is their earnings, some which investors get returned in form of dividends and buybacks, rest of which goes into the books as reserve. And what drives earnings higher is actual sales and to some extent the efficiency.

Now US Federal Reserve has raised interest rates this month for first time since financial crisis, signaling that extraordinary monetary stimulus is coming to an end (no matter how gradual). So it would now up to the economy and moreover revenue and earnings to support growth in stock market.

In that regard, this particular divergence shown in the figure (monthly), is very concerning. Total business sales, measured by US census bureau and released monthly showing signs of concern.

Though overall business sales are growing, the growth has been declining since late 2011, however since mid-2014, with drop in oil prices and intensifying in emerging market crisis growth has declined sharply and this year it has been completely in negative.

S&P 500 on the other hand has continued to move up, only on its way to close in negative this year but that is also marginally.

It is naturally making us to think, how much S&P 500 can really grow, if TBS fails to improve.