Recent models of inflation based on string theory predict the formation of a 4-dimensional network of superstrings on a cosmological scale. In this talk, I will show how the degrees of freedom living on these fundamental strings can backreact on their spacetime motion in the same way as a neutral persistent current would, allowing, therefore, the possibility of stable string loops. I will then comment on the consequences that these stable loops have for cosmology. Finally, I will also discuss the supergravity description of these string states and their identification with known solutions describing rotating dipole black rings.