Markets rally as BoJ launches negative interest rate

World stock markets rebounded Friday, ending a highly volatile month with a bang after the Bank of Japan unexpectedly slashed interest rates into negative territory for the first time. Equities in Asia and Europe rallied as traders seized on the BoJ's announcement that it would charge banks to hold their cash, in news that also sent the yen tumbling. The Bank of Japan's unprecedented decision to adopt a below-zero interest rate mirrors the European Central Bank (ECB) and the Swiss National Bank