The counter argument:
1. Absolute margin debt and its YoY growth look extreme because the stock market itself has expanded dramatically. When plotted against total market capitalization (e.g., Wilshire 5000), margin debt has risen roughly in line with the market — the ratio remains far from the frothiest historical peaks. This suggests leverage is elevated but not as systemically dangerous as raw dollar figures imply.
2. Fundamentals and growth can support higher leverage
The current rally has strong underpinnings (AI capital spending boom, robust corporate earnings growth). Unlike some prior bubbles, there is tangible productivity and profit growth behind parts of the market. High margin debt can persist and even expand in strong secular bulls if earnings keep pace.
3. Timing is extremely difficult — “the rollover” can be late or misleading
Waiting for the exact turn in margin debt growth often means sitting out significant further gains. Markets don’t ring a bell. Many investors who de-risked on similar signals in prior cycles underperformed by missing the continuation of the uptrend. Long-term equity returns have historically rewarded staying invested through volatility far more than trying to time tops.
4. Opportunity cost and behavioral realities
• Cash earns little real return after inflation.
• Forced selling from margin calls is a risk mainly in sharp, rapid declines — not a guaranteed near-term event.
• Broad diversification, quality companies, or systematic strategies (e.g., dollar-cost averaging into indexes) reduce the impact of any single leverage unwind.
5. Historical resilience of bull markets
Bull markets can last longer and go higher than most expect, especially when driven by transformative technology. Warnings based on leverage or sentiment have been early or wrong at various points in the past two decades.