Playing with fire? Margin debt most since crisis

Traders on the floor of the New York Stock Exchange.
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As investors feel emboldened by the seemingly unstoppable stock market rally, they're borrowing money at record levels to keep things going.

Margin debt—a measure of how much market participants are borrowing to buy stocks—has soared to $412.5 billion on the New York Stock Exchange. The number represents a 13.2 percent gain from the beginning of 2013 and is fully 50 percent higher than the level in January 2012.

There are two ways to look at such a data point.

One is that investors are so confident in the market that they believe they're safe by funding their purchases from other sources and the market will rise sufficiently that they'll be able to repay their debts and pocket a nice profit.

That would be a good thing.