Well one thing is Litecoin has a much larger supply (3.24x according to Coincap). In terms of market cap & supply as of today a $15k Litecoin is equivalent to ~$50k Bitcoin. The market cap of Litecoin alone would be 0.84 Trillion. It's possible I suppose but I think you'd need some pretty serious institutional buying (or gaming of the system which only lasts so long).