IBM shares suffered their most severe single-day decline in nearly four decades, plunging 26% in US trading on Tuesday.

The collapse marks the steepest drop for the technology giant since the 1987 market crash, wiping out approximately a quarter of the company's market capitalization in a single session.

The sharp repricing followed a profit warning from the computer conglomerate, triggering a violent market reaction that has left investors reassessing the stock's risk profile.

While the immediate trigger was the guidance miss, the magnitude of the sell-off suggests broader concerns about the sustainability of IBM's current valuation multiples in a shifting tech landscape.

Historical precedent offers some context for the volatility.

Similar sharp corrections in large-cap technology stocks have occasionally served as entry points for long-term investors, provided the underlying business fundamentals remain intact.

However, the scale of this decline—unseen since the Black Monday crash—indicates a significant shift in market sentiment toward the company's growth trajectory.