The party's over

The party's over.

In a note on Friday morning, Kit Juckes, a strategist at Societe Generale, wrote that the easy money has been made and things are about to get a lot harder for investors.

"Making healthy investment returns when QE-inspired asset inflation is all but played out, emerging markets are slowing, Europe is stagnant and the Fed is showing a distressing lack of leadership, is going to be really, really difficult," Juckes wrote.

And with this, Juckes is sticking a fork in the post-financial-crisis rally that has seen bond yields fall, stock prices rise, and in recent months, the US dollar rally as central banks supported markets with low rates and outright asset purchases.

On Thursday, the Federal Reserve elected to keep interest rates inside the 0%-0.25% range where they've been pegged since the financial crisis.

And so while you might think the Fed keeping rates near 0% is actually good for markets - in particular riskier assets like stocks and high-yield bonds - Juckes' point is that everybody knew these riskier assets would appreciate in price, they did (in a hug way), and now the appetite to continue buying at these levels has dried up.

In his note, Juckes cites an analogy made by Peter Tchir at Brean Capital who has written that financial markets are currently in a "Hotel California" situation. In this analogy, Tchir is invoking the famous line from the Eagles song that goes, "You can check out any time you like, but you can never leave," meaning that central banks rolled out extraordinary monetary policy following the financial crisis and now won't be able to roll it back.

And the knock-on effect, under this idea, is that prices will probably go lower as these trades are unwound.

Our editor-in-chief Henry Blodget thinks there's a chance stocks could crash 50% from here, arguing that not only are stocks overvalued, but that big declines in the stock market don't happen overnight. In short, the chaos we saw at the end of August could just be the start of a longer downturn in the markets.

Last week we highlighted comments from Nobel laureate and Yale professor Robert Shiller who said he's concerned about the continued increase in asset prices as investor confidence declines, indicating that investors are buying stocks out of fear rather than about optimism about the future.

In an interview with The Financial Times last week, Shiller said there is a "bubble element" to what we're seeing in the stock market. And these factors together make the entire situation quite fragile.

The kicker?

On Friday, the first full day after the Fed meeting, stocks got hammered while a startup launched cash into the streets of San Francisco.