The only the matter portion of the universe is 85% dark matter (26.8% of mass-energy content of the universe).
As for the question; I don't think it's right to assume that dark matter really is exotic matter. It's just a set of observations. It's something that behaves like matter (with respect to density scaling) but only seems to interact gravitationally.
Some theories posit that it's some unknown particles, others that they are primordial black holes, and some that gravity just behaves differently (MOND).
I really enjoyed Dr Angela's videos on Dark Matter [1,2]
The only the matter portion of the universe is 85% dark matter (26.8% of mass-energy content of the universe).
As for the question; I don't think it's right to assume that dark matter really is exotic matter. It's just a set of observations. It's something that behaves like matter (with respect to density scaling) but only seems to interact gravitationally.
Some theories posit that it's some unknown particles, others that they are primordial black holes, and some that gravity just behaves differently (MOND).
I really enjoyed Dr Angela's videos on Dark Matter [1,2]
[1] https://www.youtube.com/watch?v=qS34oV-jv_A [2] https://www.youtube.com/watch?v=PbmJkMhmrVI