According to Marks, we have not had a "free market" in money for a long time. The easy money policy of the Federal Reserve has to end. The only question is when.
Marks thinks the "when" is going to be in the fairly foreseeable future.
The end of the easing is obviously going to result in higher interest rates, since the easing is the reason that rates are artificially low today.
He thinks that today is a time for caution for investors because there is no way to know how the economy will do once the stimulus is removed. That is dangerous when it is combined with the fact that low interest rates have already boosted asset prices.