(Reuters) -Shares of data storage companies such as Seagate ( STX ) and Western Digital ( WDC ) have sharply outperformed the broader market this year, powered by the staggering demand for hard drives in the global race to scale up AI-related infrastructure.

Both Seagate ( STX ) and Western Digital ( WDC ) stocks are trading near record highs, having surged more than 200% this year on the artificial intelligence boom.

Western Digital ( WDC ) gained 10.5% in premarket trading on Friday after it forecast second-quarter earnings above Wall Street estimates.

"The fact that WDC has secured purchase orders extending through CY26 with five of its largest customers is a clear indication that customers are unwilling to risk falling short on storage capacity as AI-related demand continues to march higher," J.P.Morgan analysts said in a note.

Earlier this week, rival Seagate Technology ( STX ) also forecast second-quarter revenue and profit above estimates late Tuesday. Its shares have surged 20% since, and were up 1.7% on Friday.

Seagate ( STX ) and Western Digital ( WDC ) are the second and third-highest percentage gainers this year on the S&P 500, only behind trading platform operator Robinhood.

Smaller rival Sandisk ( SNDK ), spun out of Western Digital ( WDC ) in February, has also seen a five-fold jump in its stock since listing. Shares of the company, which will report its results on November 6, were up 3.1% on Friday.

The S&P 1500 technology hardware, storage and peripherals sector - which houses all three companies - has jumped more than 11% for the year and hit a record high on Thursday.

Tech giants Alphabet, Microsoft ( MSFT ), Meta and Amazon ( AMZN ) all announced plans for higher annual capital expenditures as they pour money into chips and data centers.

Global AI-related infrastructure spending could reach $3 trillion to $4 trillion by 2030, Goldman Sachs estimates.

"If you went back twelve months or twenty-four months and you asked somebody about AI, they wouldn't have talked about hard disks... It's exciting," said Martin Frandsen, portfolio manager at Principal Asset Management.