Renowned Banker Warns of Hidden Margin Debt Risk

The 'Magnificent Seven' stocks, which include NVIDIA Corp (NASDAQ:NVDA) and Apple (AAPL), have seen significant money flows. However, investors should be cautious as most portfolios are heavily concentrated in these stocks.

A renowned banker has warned about hidden margin debt, which could pose a significant risk to investors.

The SanDisk Corp (NASDAQ:SNDK) and Western Digital Corp (WDC) have disappointed investors with their performance. SK Hynix's flash crash is also a concern for the industry.