Is the stock market in a speculative bubble? Beyond mere claims, one of the most effective ways to measure investor sentiment is to observe if statements align with actions. During periods of market euphoria, traders often leverage themselves heavily to buy stocks, utilizing financial leverage provided by brokers. In this video, we delve into the concept of Margin Debt, a measure used by the FINRA to gauge the extent of retail trader borrowing. By comparing this data with historical market capitalization trends, we gain insights into whether current investor behavior suggests a speculative frenzy or cautious speculation.