Nvidia is putting real money into Taiwan's MediaTek, and investors reacted fast — the stock jumped to its daily limit at the open.

• Nvidia bought $3.5 billion of MediaTek convertible bonds, taking almost 90% of the whole offering.
• MediaTek shares locked at limit-up with buy orders piling up far beyond what was for sale.
• The tie-up should help MediaTek win more big cloud customers for its custom AI chips.
• The cash is earmarked for locking in supply — memory chips, advanced packaging materials, and pre-paid factory capacity.

Outlook: Analysts see room to raise MediaTek's AI chip revenue forecasts, and the stock is likely to stay in demand while the Nvidia partnership deepens.