Short lived arbitrage opportunities arise when prices adjust with a lag to new information. They are toxic because they expose dealers to the risk of trading at stale quotes. Hence, theory implies that more frequent toxic arbitrage opportunities and a faster arbitrageurs' response to these...

Using methods from machine learning we show that fundamentals from simple exchange rate models (PPP or UIRP) or Taylor-rule based models lead to improved exchange rate forecasts for major currencies over the floating period era 1973--2014 at a 1-month forecast horizon which beat the no-change...