Living with Mom and trading on margin. The regular investor gets in on Wall Street’s record stock borrowing binge

Sean Conlon | CNBC | October 9th, 2026

HOUSTON — During a late night at home in May 2021, Hy Luu, a 29-year-old engineering consultant, was researching how to obtain more capital to invest in shares of Tesla.

That’s when he discovered margin investing: the act of borrowing money from a broker to buy securities such as stocks, while using existing investments as collateral. Borrowing would give him more buying power, and he could pay it back as the stock appreciated. The main risk would be a margin call, or having to deposit more money into the account, if its value fell.

Not all of that debt is driven by fresh borrowing due to new borrowing decisions. For example, as equities rise in value, an investor may need to cover a short position that’s been marked to market, or valued at its current price.

Nonetheless, Sam Huszczo, chief investment officer at SGH Wealth Management, thinks the market’s bull run — which has seen multiple record highs this year alone — is feeding a shift in investor psychology, and margin debt is one sign.

“That’s greed,” the founder said, adding that it’s “not everywhere” in the market, but it’s “certainly creeping into pockets.”

“Margin, that’s only the tip of the iceberg of what we can see,” he continued. “Fear of missing out is just the emotion of jealousy with a brokerage account.”

Huszczo considers the market to actually be “way healthier” than people think. Though he recognizes that increasing margin debt and the rise of risky assets such as leveraged ETFs inject more fragility in the system.

“People need to differentiate between what’s a legitimate momentum growth investment and what’s reckless chasing,” Huszczo also said.

Huszczo shares the commonly held belief among financial advisors that investors’ portfolios shouldn’t be overly concentrated in one stock or even one sector.