I already mentioned that a paraphrase can, by changing the position of a word, change its part of speech designation. Do you agree?
Yes I agree, but my intention was simplification, not obfuscation, since several of you are having trouble in grasping this.
two new examples, materially changed and then declare that 'that', which refers to only one, is not an adverb.
Not materially changed in meaning, I think. And they are all adjectives.
Going back to the original phrase: "the market closed little changed".
This means, the market was virtually unchanged by the time it closed.
It is a description. "Little changed" is an adjectival phrase.