Traders work on the floor of the New York Stock Exchange (NYSE) in New York City.

Jeenah Moon | Reuters

The pace at which investors are borrowing money to invest in stocks has cooled substantially, raising concern that the stock market may be due for a fall.

Recent FINRA data shows the annual growth in margin debt fell to 31.4% in September from 53.7% in May, Bank of America technical strategist Paul Ciana pointed out in a Friday note. Ciana warned that slowing borrowing momentum from extreme levels has been associated with previous market peaks.

May's growth rate in 2026 was the fourth highest since 1998, according to a BofA analysis. The three higher extremes took place in 2000, 2007 and 2021 — all of which preceded stock market declines.

Earlier this year, borrowing was increasing much faster than stocks were rising.…