There were no cold hard facts to justify the swing in sentiment: it was simply that investors figured that their previous bearishness had been overdone. Sterling ploughed its own lonely furrow, weakening on most fronts. In large part that was because of uncertainty created by today's European Council meeting that will allegedly decide Britain’s future in the EU.
The Aussie did reasonably well as a result of the improved optimism among investors, strengthening by two cents against sterling and holding steady with the US dollar. Its performance was spoiled, however, by some less-than-inspiring employment data: Australia unexpectedly lost 8k jobs in January, pushing unemployment up from 5.8% to 6%.