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Altera had a market value of $10.4 billion as of mid Friday. The company makes chips called programmable logic devices (PLD).
Altera stock was briefly halted Friday afternoon. When it opened up just before 3:40 p.m. ET, the stock rocketed to a more than 28 percent gain on the day. That move represented the company's largest one-day increase ever.
Intel stock rose more than 6 percent after the report.