Quantum Stock Surges 89% in 90 Days Amid S&P Index Inclusion

Quantum shares jumped 89% over three months following S&P index inclusion. Analysts debate if the $26.10 price fully reflects the company's value.
Key points
- Quantum shares gained 88.99% over the last 90 days following S&P index inclusion.
- One valuation model estimates fair value at $24.00, suggesting the stock is 9% overvalued.
- A different cash flow model projects a value of $63.74, indicating potential upside.
Quantum shares closed at $26.10 after a 90-day gain of 88.99%. This sharp rise coincided with the company's addition to the S&P Technology Hardware Select Industry Index.
The one-year total shareholder return reached 127.75%. Index inclusion typically forces passive funds to buy the stock, creating immediate demand pressure on the shares.
Index inclusion drives passive buying
Yahoo Finance reports that this move changes how large funds treat the stock. The inclusion mandates index trackers to hold the shares in their portfolios.
This structural demand often precedes broader market recognition of a company. It signals that Quantum now meets the liquidity and size standards for major benchmarks.
The timing aligns with the launch of Quantum Autonomous Data Management. The company also appointed a new Chief Information Officer on September 14, 2026.
Valuation views remain sharply divided
One widely followed narrative anchors fair value at $24.00. This places the current $26.10 price 9% above that target level.
Supporters point to a 29% year-over-year increase in subscription annual recurring revenue. This shift toward recurring income is expected to stabilize cash flow and margins.
A separate discounted cash flow model suggests a value of $63.74. This figure implies the current stock price is significantly undervalued relative to future cash flows.
Financial risks persist despite growth
The company reported a net loss of $239.1 million in the US. This figure raises concerns about the sustainability of the recent revenue growth.






