Nothing goes up forever. Not the Federal Reserve's balance sheet, not global debt levels, and not stock markets... even when governments don't shut down.
Precisely because the Fed's balance sheet ballooned from $869 billion in August 2007 to over $3.6 trillion (and counting) today, and in spite of ballooning U.S. and global debt levels, U.S. equity benchmarks have been inflated to precarious heights.
"Houston, we have a bubble."
While the sky-high Fed balance sheet and rising global debt levels are their own bubbles, when they diverge - meaning, when the Fed starts to taper as global debt inflates - look out.
If the Fed-induced pump priming of financial assets isn't backstopped by strong and real global GDP growth, the increasing debt burden of the world's citizens will act as the ultimate pinprick that explodes the United States' inflated financial assets bubble... and other global bubbles.