(Bloomberg) -- Cryptocurrencies saw few gains on Tuesday, while price swings surged on Asian exchanges after South Korean President Yoon Suk Yeol declared martial law as the country faces a political deadlock in parliament.Most Read from BloombergAs Wars Rage, Cities Face a Dark New Era of Urban DestructionRiyadh Metro Partially Opens in Bid to Ease City’s Traffic JamsFive of the six largest digital assets were in the red, with only market bellwether Bitcoin seeing marginal gains. Bitcoin has se