Margin debt is the total amount of money investors borrow from brokerages to buy securities, reaching a record high of roughly $1.53 trillion. It acts as market leverage that magnifies both gains and losses, but high levels signal heavy speculation and potential instability.

JPMorgan's Jamie Dimon warns of high leverage: 'Somebody will disrupt the market'JPMorgan Chief Executive Officer Jamie Dimon warned that leverage across financial markets remains elevated, adding that investors should be mindful that hidden borrowing could amplify market disrupti...www.cnbc.com