Cerebras Systems Inc. (CBRS  ) and Cisco Systems Inc. (CSCO  ) were sinking Thursday despite both companies delivering fresh evidence that the AI infrastructure boom is alive and well. The problem may not be demand. It's what investors now expect companies to do with it.

Cerebras was down 13% and Cisco about 8% at the time of writing.

AI Demand Isn't The Problem

Cerebras posted record core revenue of $209.9 million, up 103% year over year, with core cloud and services revenue surging 287%. Remaining performance obligations reached $25.4 billion, and the company raised its full-year guidance.

Cisco also reported strong AI demand. It booked $4 billion of hyperscaler AI infrastructure orders in the fourth quarter, taking fiscal 2026 orders to $9.3 billion, and expects $7.5 billion of hyperscaler AI revenue in fiscal 2027. Revenue rose 18% to $17.25 billion, beating estimates.

Yet Wall Street sold both. So what was missing?

Wall Street Wants Acceleration, Not Just Growth

AI infrastructure winners are increasingly judged on their "rate of acceleration," Jake Behan, Direxion's head of capital markets, told Reuters. Cisco entered earnings with considerable optimism already priced in, he said, so strong results were treated as confirmation of the AI story rather than a new catalyst.

Cerebras guided third-quarter core revenue to $214 million to $216 million, implying just 2.4% sequential growth at the midpoint, despite revenue more than doubling from a year earlier. Core gross margin is also expected to fall to 38% to 40% before recovering in the fourth quarter.

For investors, triple-digit annual growth may not be enough when sequential growth is slowing.

The AI Trade's New Test

Prediction-market traders remain skeptical that the broader AI boom is about to break down. Polymarket puts the odds of a severe AI-industry downturn by year-end at 14%, down from 27% in late July, on roughly $2.9 million in trading volume.

Morgan Stanley analysts said "execution remains the key debate" for Cerebras given the scale and speed of the capacity build needed to support its growth.

Before the reports, investor Dan Ives called Cisco and CoreWeave "pieces of the puzzle" for the AI trade, arguing the story is shifting beyond capex toward monetization.

The reactions to Cisco and Cerebras show investors are looking for more than evidence of strong AI demand. They also want to see that demand translate into faster revenue growth and higher margins.