The SoftBank-owned outfit said it couldn’t provide full-year guidance due to the looming spectre of US tariff chaos. Shares slumped as much as nine per cent in after-hours trading, sliding to $113 a pop after it offered a conservative $1 billion to $1.1 billion forecast for the current quarter—barely scraping Wall Street’s low end.

Arm’s chief financial officer Jason Child admitted the company had “lower visibility than normal” into customer demand. He said revenues in the quarter to 31 March were not directly hit by the latest “reciprocal” tariff plans, but the firm was too nervous to call the future.

Its numbers were otherwise on track. The March quarter brought in $1.2 billion, up 34 per cent year on year, while net income slipped 6 per cent to $210 million. For the full 2025 financial year, revenue jumped 24 per cent to $4 billion.

But the chip market is starting to look twitchy. Job’s Mob and Nvidia, two of Arm’s biggest clients, are exposed to supply chain tremors. Nvidia in particular has been kneecapped by fresh US export restrictions to China and could see more limits soon.

The US government's latest tariff sabre-rattling has pushed Washington into a full-blown national security review that might result in extra charges on semiconductors and consumer tech. While Apple and others got a temporary reprieve, it’s hardly a vote of confidence for stable planning.

Arm said its slower outlook was mostly down to new licensing deals not being finalised yet. It makes its money flogging licences and royalties on chip designs used in everything from phones to AI gear.

Despite this wobble, Arm was one of the poster children of 2024’s AI gold rush. It re-listed in the US in September 2023, and its parent SoftBank still clings to around 90 per cent of the stock. Shares may be off about three per cent since January, but considering the political flak flying around, that’s not bad.