I believe that it is stock knowledge...
Sinearch ko at ito ang nakita kong magandang explanation...
“stock knowledge” is defined as the set of structured, systemic, and contextual information that one has already learned and internalized; it is preexisting knowledge, as opposed to knowledge that one doesn’t have or has yet to learn and understand.
“stack knowledge,” whatever it means isn’t part of my stock knowledge yet. it is a noun phrase, a cursory search on the web has convinced me that “stack knowledge” doesn’t exist in the English lexicon at all.
The noun phrase “stock knowledge” is clearly a strong collocation that consists of the noun “knowledge” modified by the adjective “stock” in the sense of “commonly used or often brought forward.” On the other hand, when looked upon as a noun phrase, “stack knowledge” doesn’t qualify as a collocation because it fails to convey a clear and identifiable meaning by association. Differentiating “stock knowledge” from “stack knowledge” is therefore like differentiating apples from desktop computers, which is clearly not a very meaningful exercise.
"Stock vs. Stack"
