The BlackRock Global Ascent hedge fund has lost 9.4 percent this year and investors in the $1 billion fund were notified over the last week that it would be closed down, according to a person with direct knowledge of the firm’s decision. The hedge fund — which as recently as two years ago had $4.6 billion in assets under management — is now almost completely cashed out, that person said. BlackRock is the latest firm to wind down in a string of hedge fund closures, many of them focused on global macro strategies. Macro hedge fund managers have struggled to...