CCBRSCerebras Systems Inc.

Cerebras builds a processor the size of an entire silicon wafer — instead of many separate chips.

Normally hundreds of dies are cut from a wafer and then wired together; moving data between chips is what becomes the bottleneck when training large models. The company leaves the wafer whole: compute and memory sit on one piece of silicon and the exchange happens inside rather than across external buses.

The approach wins on speed for certain workloads but demands different development tools — and the whole industry is accustomed to the dominant vendor's ecosystem. Hence the main risks: revenue concentrated in a few customers, dependence on the market's willingness to change platform, and a need for capital. The company pays no dividend.