> Built on a sparse Mixture-of-Experts architecture, Step 5 Preview has 600B total parameters, with 27B active per token, and supports a 1M-token context window and vision input.
> Step 5 Preview scores 44 on the Artificial Analysis Intelligence Index.
> The model will be released with open weights on October 15.
I guess being Chinese company they decided to skip version 4, while also giving impression to be on the similar iteration with leading companies (claude opus 5).
I wonder if other Chinese labs like Kimi/Moonshot will follow suit.
Moonshot has already teased K3.1 so not likely
K3.1 would likely be a deeper/longer post-train from K3, so that’d make sense.
It’s all marketing anyways, but that’s at least how a lot of labs have been naming things (sometimes).
Another possible reason is that the number 4 is considered unlucky in traditional Chinese culture.
Parent commenter hinted at that. Yet DeepSeek has released their V4 which was hugely successful, and even their new architecture is marked V4.1. Qwen internals mark their Flash-Next model, also very compelling, as "qwen4exp". So both of them are bucking the negative stereotype.