MediaTek (TWSE: 2454) finished up 9.94% at NT$4,315, a gain of NT$390, as reported by Google Finance. That number isn't a coincidence. Taiwan caps a stock's daily move at 10%, so MediaTek went limit-up and simply stopped — Barchart reported buyers hitting the daily limit. The demand had nowhere left to go.

What happened

Nvidia bought $3.5 billion of MediaTek convertible bonds, part of a $3.9 billion overseas convertible offering that is the largest MediaTek has ever done, per Reuters. Alphabet quietly took part in the same offering, Barchart reported.

A convertible bond is a loan that can turn into shares later. If MediaTek stumbles, Nvidia gets repaid like any lender. If the stock keeps climbing, Nvidia converts and keeps the upside. It's how you take a very large position in a company without buying it.

Why it moved

The cash is the headline. The plumbing is the actual story.

MediaTek is adopting NVLink Fusion, Nvidia's interconnect standard. Here's why that matters. Amazon, Google and Microsoft are all designing their own AI chips to stop paying Nvidia's margin. Nvidia can't stop them, so it's doing the next best thing — making sure those in-house chips still plug into Nvidia's racks, memory and networking. MediaTek is one of the firms that designs those custom chips for other people. It just went from being part of the threat to being a sanctioned on-ramp.

Two numbers show what got repriced. MediaTek's custom AI-chip unit is targeting $2 billion of revenue in 2026, and it has lifted its data-centre market-share goal for 2027 to 15–20%, up from 10–15% (Barchart). Nvidia's Jensen Huang called MediaTek "one of the world's great semiconductor companies"; MediaTek CEO Rick Tsai said the deal "strengthens a collaboration that spans cloud AI infrastructure, local AI computing and automotive."

The business

Before treating this as an AI pure-play: smartphone chipsets were 59% of MediaTek's revenue in Q4 2025. The rest is Smart Edge (up 18% year-on-year that quarter), connectivity — 5G modems and Wi-Fi 7, over $3 billion in 2025 — power ICs, automotive under the Dimensity Auto line, and the new data-centre ASIC unit. Today's catalyst lands on the newest and smallest slice of the company.

Is it expensive?

At Friday's NT$3,940 close MediaTek traded on a trailing P/E of 63.8 and a forward P/E of 37.4, with a market cap of roughly $218 billion — the 89th most valuable listed company in the world (StockAnalysis; CompaniesMarketCap). Today's jump pushes the trailing multiple past 70.

That is rich in absolute terms, and it isn't being paid for current earnings: trailing revenue grew just 3.5% while net income fell 9.1% and EPS fell 9.2%. The multiple is a bet on a data-centre business that mostly hasn't arrived yet.

Against the obvious alternatives: Broadcom — the incumbent in custom AI ASICs, and the company MediaTek is now aiming at — trades on a trailing P/E of 61.6 (forward 23.5) at a $1.75 trillion market cap. Qualcomm, MediaTek's day-job rival in phone chips, is on a trailing P/E of 19.7 (GuruFocus, 1 Sep). So MediaTek is priced roughly like Broadcom while still earning most of its money like Qualcomm. Its 52-week range is NT$1,130–4,970 and it's up around 200% this year (Yahoo Finance) — even after today it sits below its high.

Who it touches

• Qualcomm — its phone-chip rival just got a $3.5bn war chest and Nvidia's public blessing in data-centre silicon, a market Qualcomm is also pushing into.
• Broadcom — the custom-ASIC incumbent now faces a funded challenger holding a formal Nvidia interconnect tie-up.
• Indian phone buyers — MediaTek is still the world's largest smartphone chipset vendor at 32% share in Q1 2026 versus Qualcomm's 23% (Counterpoint), but that's down from 38% a year earlier as memory shortages squeezed entry and mid-range phones — precisely the price bands India buys most of.
• Nvidia shareholders — another few billion dollars of Nvidia's balance sheet is now funding a partner rather than sitting in cash.

The one risk

Circular financing. Nvidia's upside on this bond depends on MediaTek's AI business growing, which depends on adoption of NVLink Fusion — a standard Nvidia controls. Analyst Stacy Rasgon said the deal "will clearly fuel 'circular' concerns", and it follows Nvidia's $30 billion equity investment in OpenAI in February 2026 and a $105 billion infrastructure guarantee for OpenAI's Ohio data centre in August (TechTimes). Huang's answer: "This is not circular because obviously they do their own business and we do our own business." Alphabet buying into the same offering is the strongest counter-argument, since it had no NVLink incentive to.

The operating risk is simpler. Almost six in every ten revenue dollars still come from a phone-chip business that is losing share, and the data-centre ramp is a 2027 story. If that ramp slips, a 60–70x multiple sitting on falling earnings has a long way to fall.

As of 1 Sep 2026, 21:07 IST. Sources: Reuters via Investing.com, Investing.com, Google Finance, Barchart, Yahoo Finance, StockAnalysis, CompaniesMarketCap, GuruFocus, StockAnalysis (AVGO), Counterpoint via The Tech Outlook, TechTimes, Nikkei Asia. All prices and multiples as reported by those sources, not live data. For discussion and education only — not investment advice. Verify before acting.