Bets on stronger yen vs dollar hit more than 5-year high

LONDON, Feb 9 (Reuters) - Currency markets upped bets on gains for the yen in the next month to their highest in more than five years on Tuesday, a reflection of the scale of market stress which has sent investors scuttling for the traditional security of Japan.

One-month risk reversals in the yen until late last year indicated a strong bias towards more gains for the dollar but in a slide since October have now flipped to their weakest since May 2010.

The equivalents in 3-month and 6-month contracts - used standardly by big global importers, exporters and speculators to hedge currency exposure - showed the biggest bias toward a weaker yen since late 2011.

A 6 percent rise for the yen so far in February also drove implied volatility of the currency to its highest in more than two years. (Reporting by Patrick Graham, editing by Anirban Nag)