(Bloomberg) -- Investors continued to pile into some Korean stocks seen as related to superconductors amid claims about a breakthrough in the technology, even as the exchange warned of speculative bets and unfair trades.Most Read from BloombergFitch’s US Credit Downgrade Sparks Criticism Along With UneaseMissing Goldman Sachs Analyst Confirmed Dead by New York PoliceS&P 500 Has Worst Day Since April After Big Rally: Markets WrapCanada PM Justin Trudeau Splits With Wife Sophie GregoireHere Are th