I didn’t expect to be writing about Wolfspeed, STMicro, and On Semiconductor. But the ticker tape this week told a story I couldn’t ignore. These three power chip makers rallied hard on news that Nvidia’s next-gen Vera Rubin platform is ramping up. The headline: “AI demand fuels power chip surge.” The subtext: the entire blockchain mining infrastructure—from ASIC farms to GPU rigs—sits on a fragile substrate of semiconductor supply. And that substrate is about to get a lot more expensive.
I’ve been tracking the power chip ecosystem since 2020, when I first started matching silicon carbide (SiC) supply curves against Ethereum mining hash rates. Back then, the story was simple: SiC and GaN (gallium nitride) were the future of efficient power conversion. But the interplay between AI data centers and crypto mining is a structural tension I’ve watched evolve in real time. Now, with Vera Rubin, that tension is about to snap.
Context: The Power Chip Supply Chain 101
Let’s get the basics straight. Power semiconductors aren’t 3nm logic chips. They’re the workhorses that convert and regulate voltage in everything from EV inverters to server power supplies. For crypto miners, they’re inside the PSUs (power supply units) that turn 240V AC into the 12V or 48V DC that ASICs and GPUs need. For AI, they’re inside the 1kW+ racks that power Nvidia’s H100 and now Vera Rubin.
The three companies in the news—Wolfspeed, STMicro, and On Semiconductor—are IDMs (integrated device manufacturers). They design, fab, and package their own chips. Wolfspeed is the SiC substrate king, supplying the raw material for high-voltage devices. STMicro is a broad-line power IDM with deep automotive roots. On Semi is similar, with a strong focus on industrial and automotive. Their rally this week signals that the market expects Vera Rubin to drive a step-change in power chip demand.
But here’s the catch: the power chip supply chain is already strained by automotive electrification. The AI demand surge comes on top of that. And the crypto mining industry, which operates on thin margins, will feel the squeeze first.
Core: The Vera Rubin Effect on Power Chip Supply
Let’s unpack the Vera Rubin platform. It’s Nvidia’s next-generation GPU architecture, expected to be the successor to Blackwell. The key detail: power consumption per GPU is expected to exceed 1.5kW, and the entire rack system could draw 20kW or more. That means the power delivery network—the voltage regulators, the DC-DC converters, the 48V buses—must be more efficient and more compact.
This isn’t just about SiC. The board-level power delivery for Vera Rubin will likely use GaN HEMTs (high-electron-mobility transistors) for the 48V-to-1V conversion, because GaN can switch faster and handle higher frequencies than silicon. The infrastructure-level power (UPS, PDU, etc.) will use SiC MOSFETs for their higher voltage tolerance and lower losses.
Now, look at the capacity picture. The industry is transitioning from 150mm SiC wafers to 200mm. Wolfspeed’s Mohawk Valley fab is a 200mm SiC facility, but it’s been struggling with yield and cost. STMicro and On Semi are also building out 200mm SiC lines. The problem? These fabs take 12-24 months to ramp, and the capital expenditure is enormous. Wolfspeed alone has spent billions with little to show in terms of profit.
The hidden signal here: the power chip supply for Vera Rubin will be tight. And when supply is tight, prices go up. Crypto miners, who are price-sensitive buyers of power chips (through their PSU procurement), will face higher costs. I’ve seen this before. In 2021, when the global chip shortage hit, GPU prices went to the moon—not just because of demand, but because of power chip constraints. The same cycle is about to repeat.
Contrarian: The Rally Is Overhyped
But here’s where I break from the consensus. The rally in Wolfspeed, ST, and On Semi might be a narrative trap. The market is pricing them as direct beneficiaries of Vera Rubin, but the real winners are likely to be different players.
First, the board-level power supply for AI GPUs is dominated by companies like MPS (Monolithic Power Systems), Infineon, and Navitas Semiconductor (a GaN specialist). On Semi and STMicro are strong in automotive, but their server power business is smaller. Wolfspeed is a pure SiC play, and SiC is more relevant for infrastructure power (UPS, PDU) than for the GPU board itself. The market might be confusing “AI power demand” with “SiC demand,” but the immediate beneficiary of Vera Rubin’s board-level power is GaN, not SiC.
Second, the supply chain for GaN has its own bottleneck: gallium. China controls the majority of the world’s gallium supply, and export restrictions have already been imposed. If those restrictions tighten, GaN wafer production cost will spike, and the entire AI power supply chain faces a material input shock. The three companies in the rally are not immune. Wolfspeed uses SiC, which doesn’t require gallium, but STMicro and On Semi have GaN product lines. They could be exposed.
Third, the financial health of these companies matters. Wolfspeed is burning cash. Its Mohawk Valley fab is a drag on earnings. The rally might be a short squeeze or a narrative-driven pump rather than a reflection of fundamental demand. I’ve seen this pattern before: a headline about a big customer (Nvidia) sends the stock up, but the underlying capacity constraints and capital structure mean the company can’t capture the value.
Takeaway: What This Means for Crypto Miners
You don’t wait for the moon to hedge your mining operations. The takeaway is actionable: start monitoring GaN and SiC inventory levels. If the power chip supply tightens, the cost of PSUs and ASIC rigs will rise. The margin compression in mining will accelerate. The play here is not to short the chip stocks—that’s too risky. The play is to lock in PSU contracts now, before the Vera Rubin ramp triggers a supply shock.
I’m already adjusting my portfolio. I’m reducing exposure to mining hardware ETFs and increasing positions in GaN-focused companies like Navitas. I’m also watching the gallium market closely. If China tightens exports, the entire AI power supply chain—and by extension, the crypto mining hardware chain—will face a structural shock.
The market’s structural integrity is being tested again. The question isn’t whether Vera Rubin will drive demand; it’s whether the supply chain can handle it. My bet is: it can’t. Not without pain. And the crypto miner will be the first to feel it.